How it all works

Nothing here is complicated to use (I hope), but a few things are tucked away. Here's the tour. If something's still unclear, tell me and I'll fix the page (or the app).

The app chooses scales and lines by rules; How it decides says which. A word you don't know? The Glossary has it.

The short version

Pick a tune from the library. Search it, or narrow it by Style and Key. Style groups the charts' styles into a few families (medium swing, up-tempo swing, ballad, blues, Latin, waltz, even 8ths & funk, other); each tune keeps its own style, which sets the click's tempo.
Choose your instrument from the Instrument menu in the toolbar. The sheet is rewritten for it.
Practice from the screen, hit Focus to get rid of everything but the music, or print it.

That's genuinely it. Everything below is for when you want more.

The sheets

Changes is the default view, where a chart opens: the tune as a lead sheet without the melody, in slashes, four bars a line (two on a phone; Bars per line changes it), with the key written in wherever it moves. Each chord's Roman numeral and scale can go under it, the why behind the scales: ii7 V7 Imaj7 in one key, then a V7/ii borrowing from the next. Numerals and Scales turn those rows on; they start off.

From 3rd and From 7th put guide tones on the Changes staff in place of the slashes: one note a chord, the 3rd or 7th that tells you which chord you're on, moving as little as it can. Only one line shows at a time. Try singing or playing one line all the way through the tune; it's a great way to learn the changes. How a line is built is in How it decides.

Note pins: with a guide tone line on, each chord's 3 or 7 under the staff opens its note: ▲ ▼ move it a half step, to any pitch in your range, ⇈ ⇊ an octave. The line plays your note there, drawn in colour and labelled by its degree from the chord's root (♯11, ♭9, 13), and re-fits from it, stepping to the nearer guide tone; move it back to the line's own note and the pin clears. On the labels, ← → walk the line, ↑ ↓ move the pin a half step, ⇧↑ ⇧↓ an octave, and Backspace clears a pin (the keys are under On a guide tone line, below). ⌘Z undoes a pin, Reset note pins in the ⋯ menu clears them all, a share link carries them, and an edit to the chart keeps a pin whose chord stays. How a pinned note is placed is in How it decides.

Scales is one staff per chord, with the scale that goes with it, in the order the tune runs. Each staff is labeled with where it is in the form, the chord and the scale. Practice works on this sheet.

Arpeggios is one staff per scale line, its chord's arpeggio: 7th Chord over two octaves, Extended up through the 9th, 11th and 13th, or Triad pairs, the chord's triad pair as six triads through their inversions, arpeggiated or as block chords. How the triads are ordered is in How it decides.

Patterns runs a scale sequence over each scale line, one staff a line: 1 2 3 4, thirds, triads, stacked fourths and more, or one of your own, written as steps (+2 −1 is up a third, back a step). Scale steps through the scale and Chord tones through the chord. Up, Down or Up & down.

How a guide tone line is built

It's moved to How it decides, with the rest of the app's choices.

The controls

The toolbar above the sheet, by what you're doing with it. On a phone they're under Controls.

Reading it on your instrument

Instrument: Charts are always written in concert pitch, and the sheet is transposed for you: trumpet, clarinet, tenor and soprano in B♭, alto and bari in E♭, horn in F, and trombone, tuba and bass in bass clef. Piano, vibes, guitar and flute read concert; for oboe, violin or any other treble C instrument, choose Flute. Pick the pitch first (Concert, B♭, E♭, F or Bass), then your instrument in it. Piano until you choose; your choice is remembered. The Instrument button shows what's set (Piano · F3–E6) and opens a panel with the pitch, the instrument and Lowest and Highest note, the range every line keeps to.
From key, From root, or From any note: From key, where every chart starts, begins every scale on the tune's key note, written for your instrument. From C (or any other note in the same list) starts every scale on that note instead. Both are sneaky good: the staves line up, so you can see exactly which notes change from chord to chord and which stay put. From root starts every scale on its own chord's root: the D Dorian on D, the G Mixolydian on G.
Show: Intervals: On the Scales sheet, Show holds Intervals. It labels each note against the chord's root (1, 9, ♭3, 11 and so on). Handy while you're learning what each note does. It starts on; switch it off if you don't need it (that's remembered too). It's on screen only, so printed sheets stay clean.

Every line keeps to your instrument's range: Written ranges.

Seeing the analysis

Analysis: On the Changes sheet, Numerals and Scales turn those rows on and off.
Line: Off, Guide Tones (From 3rd or From 7th) or 7th Chords, each chord's arpeggio in the pattern you choose, in quarters, eighths or sixteenths as the chords allow. A line's details (From 3rd or From 7th, the pattern, Approach) open from the › beside it, Line options. Exercise, at the top of Line options, picks a Line with a rhythm by name (Exercises). Under Guide Tones, Approach leads into each chord's guide tone with a short figure of eighths, played at the end of the chord before: a semitone below or above, an enclosure and more. Under 7th Chords and the cells, with Superimpose off, it leads into each chord's first note the same way. Random deals a figure to each chord, new every time you open the chart; Shuffle deals again, a share link carries the deal, and a chart saved as yours keeps it.

How each line picks its notes: the 7th Chords line, and how a guide tone line is built.

Superimposing

Superimpose: Puts a row under the chords: Off, Pentatonic (each key area's minor pentatonic, or, ranked against Chord, each chord's, Built on the degree you choose) or Hexatonic (each chord's best triad pair from its scale, such as G/Am over Cmaj7, or, ranked against Key, one pair for each key area, its IV and V triads: F/G in C; how) or Quartal (each chord's best stack of fourths from its scale, such as D G C F over Dm7, of three or four notes, perfect fourths only if you like, under Quartal options; how) or Upper structure (each chord's upper-structure triad read over it, such as A♭/C7 over C7 altered, Levine's choices first over a dominant; how).
Pentatonic, Triad pair, Quartal and Upper structure lines: While Superimpose is Pentatonic, the Line's 7th Chords becomes Pentatonic: each chord's labeled pentatonic in four-note cells; Leave out picks the note each cell drops. While it's Hexatonic, it becomes Triad pair: each chord's labeled pair a triad at a time, from the note nearest the last, or in Walt Weiskopf's Climb or Arpeggios 1 3 5 8 shape (how). While it's Quartal, it becomes Quartal: each chord's labeled stack of fourths, whole, then its next stacks (how). While it's Upper structure, it becomes Upper structure: each chord's labeled triad, whole, then its next triads (how). Each goes up, down or both by turns. The 7th Chords pattern list also holds Cells, after Randy Vincent's Building Solo Lines From Cells: a four-note cell on each chord, two beats each, read through its scale. Order plays each cell as written, reversed, rotated or with its pairs swapped. For a cell system, Phrase is on: each cell is chosen to step into the next cell's first note, across the chord change too. Turn it off to play the system as written. The Chromatic cells add a ♭9, a ♯5 or a passing tone over a dominant (any other chord plays its arpeggio); II–V chromatic plays 3 5 7 ♭9 on a dominant and 1 3 5 7 on every other chord, as on the II of a II–V.

Which pentatonic and which pair: how Auto chooses.

Choosing a level

Level: How fancy the scales get. Basic leans on pentatonics, Standard is the usual chord-scale for each chord, Advanced reaches for bebop, Lydian and altered colors, and Random deals every chord its own inside scale; Shuffle deals a new hand. It's a view setting, like the instrument: it isn't saved into the chart, and a scale you picked yourself plays at every level.

What each level reaches for: Scale levels.

Alternate changes

Some library charts carry a second set of changes for the bars where a common substitution is played (passing diminished chords, a bebop bridge's ii–Vs). The other bars are shared. A chart that has them shows Changes in the toolbar above the sheet; a chart without them looks as it always did.

Standard · Alternate: Which set is the main one. Every sheet plays it: the Changes, the Scales, the arpeggios and patterns, the guide tones, your picks and Practice. Each set keeps its own picks and Practice choices, so flipping back finds them as you left them. A sheet playing the alternates says Alternate changes under its title, printed too.
Other changes: On the Changes sheet, shows the other set's chords small above their bars, as a Real Book prints them. Flip the main set and the two swap places. Off hides them.

Both settings are remembered per chart in this browser and travel in a share link.

Editing alternates. While you edit on a wide screen with Standard playing, a small line above the bars takes each bar's alternate. Click + alt (or a bar's alternate) and type its chords: Tab moves to the next bar, Shift+Tab to the one before, Enter keeps it, Esc cancels. Leave it empty to remove the bar's alternate. A bar that goes on holding an earlier alternate shows that chord in italics. Chords the alternate set already plays there (the standard changes, or a chord held from before) aren't kept.

With Changes set to Alternate, the big chords are the alternate set. Retype a bar both sets share and it becomes an alternate; retype it back and the alternate goes. Tapping a chord sets its scale and function as usual: on an alternate bar it sets the alternate's, on a shared bar the shared chord's. An alternate can't be held. Adding, deleting or splitting bars, pasting and new sections act on both sets. On a phone, switch to Alternate and tap a chord. A repeated section shows its alternates but can't be given new ones on the line: write the section out first.

Reharm. On the Changes sheet (not while editing), click a chord to see substitutions for it: a tritone sub, the related ii, a back door and more, each with its chords, functions and why it works. Which ones depends on the sheet's level. Choose one and it's written as the bar's alternate, Changes switches to Alternate, and the chord you replaced shows small above. Click it again to choose another or go Back to standard. A chord in a repeated section is reharmed in every repeat. On a chart that already has alternates, those play too. A library chart keeps the change as your version, as any edit does. How these are chosen

To reharmonize the whole tune at once, choose from Reharm beside the Changes control: a tritone sub on every V7, a ii before every dominant, or the back door into the tonic. It leaves chords with a scale you wrote and bars that already have an alternate, and says how many it changed. Reset, at the foot of the same menu, takes the alternates back to the chart’s own (none, on a chart of your own) and keeps everything else. How a preset works

Under the Changes sheet of any chart with alternates, Standard and alternate shows each place the two sets differ: each set's guide-tone line through it on a staff, each chord's symbol over its note, and what the alternate does there, such as a tritone sub's 3rd and 7th exchanging and its bass moving down a half step. How this is worked out

Rhythm

The sheets say which notes to play. A rhythm says when. On the Changes sheet with the Line off, the sheet stays a lead sheet, four slashes a bar, and the rhythm shows on a card over the first line: one cycle of it, in slashes with stems, beams, rests, ties and accents, to play over the changes. With a Line on, the Line plays in the rhythm. The Rhythm control shows the same card as you choose. It's a view setting, like the level: it isn't saved into the chart. It shows from the Intermediate interface up.

Rhythm: In the Line's options, Rhythm is Off or a rhythm from one of three families. With a Line on, the Line plays in the rhythm. The pulse is quarters, 8ths, triplets or 16ths.
Exercises: In Line options (Intermediate), Exercise names a bundle of a Line, a rhythm and its phrasing, as a teacher would: Guide tones; Guide tones in half notes; Guide tones with pick-ups; Arpeggios in 8ths; Arpeggios in 8ths, anticipate ½; Arpeggios in 3; Arpeggios, 4 from 1; Cells in 8ths with a pick-up; Cells in 16ths, strong beats; Up the groups. Four of them are Everything's, with the controls they set: Guide tones with pick-ups and Cells in 8ths with a pick-up (Start), Arpeggios in 8ths, anticipate ½ (Timing), and Up the groups (Groups). Listen for the guide tone struck on its chord's first half-note beat (Galper's target, landed and left), the two notes into each guide tone from the chord before (his pick-up), each arpeggio begun a half-beat early on the and before its chord (Bergonzi's anticipation), with Accents on, the accents of 8ths in 3 drifting across the beats (Saindon's units), four 8ths from beat 1 and a rest to the bar (Bergonzi's runs), each cell led in by one note, a chord tone struck on 1 and 3 whatever the cell is doing, and a grouping that climbs from 3 to 7 a section at a time (Saindon's mixed phrasing). The rhythm's card shows under the choice. The controls themselves (Approach, Rhythm, Start, Timing and the rest) are under More options, and a combination of your own reads as Custom; the exercise follows the settings in force, whatever set them. Choosing one turns Superimpose off, so the sheet draws its Line. Up the groups is the chart's: another chart reads Arpeggios in 3 until you choose it there too. Every other exercise follows you from chart to chart.
Units: After Ed Saindon's Exploration in Rhythm, Vol. 1: Rhythmic Phrasing in Improvisation (pp. 7–8). A unit is a group of 2 to 7 pulses, repeated from the first beat and ignoring barlines. In sets the group, and Variation shapes it: with accents, no accents, with rests, rest last, syncopated or tied. Saindon's bracket under the staff marks the unit's first statement, and again the first at each bar where it is back on one. The caption names the cycle, for example back on one every 5 bars. That counts the unit and the bar in pulses: 8ths in 5 over 4/4 is back on one every 5 bars, 8ths in 4 over 3/4 every 2. Where the time signature changes, the caption lists the bars.
Tuplet pulses: From the Everything interface, Units also come at six tuplet pulses, after Ed Saindon's Rhythmic Patterns (ch. 10) and Jerry Bergonzi's Inside Improvisation Vol. 4 (ch. 24): quarter-note triplets (3 in the time of 2 beats), quarter-note quintuplets (5 in 4 beats), 8th-note quintuplets (5 in 2 beats), 16th quintuplets (5 in a beat), sextuplets (6 in a beat) and septuplets (7 in a beat). Your rhythm… takes them too, as 4t:, 4q:, 8q:, 16q:, 16t: and 16s:. Each bar draws its tuplets with their number over the bracket, and a note held through whole tuplets merges into one plain note. A tuplet never crosses a barline, so a bar that doesn't hold a whole number of its tuplets (2 beats each for quarter-note triplets and 8th-note quintuplets, 4 for quarter-note quintuplets) plays in plain quarters, or plain 8ths for 8th-note quintuplets: a 3/4 bar under quarter-note triplets, say, or every bar of a 3/4 tune under quarter-note quintuplets. The unit keeps counting through that bar.
Mixed phrasing: From the Everything interface, a unit on the Changes can change its grouping as the tune goes, after Ed Saindon's mixed phrasing (Rhythmic Patterns, p. 12) and Jerry Bergonzi's groupings (Inside Improvisation Vol. 4, ch. 14, “Mixing groups”, p. 64). In Line options, Groups is One (the unit's own), Up (3 4 5 6 7), Down (7 6 5 4 3) or Your list… (numbers 2 to 7, separated by spaces), and Step says when the next grouping comes: at each section, at each change of key area, or every 2, 4 or 8 bars. A list shorter than the form starts over. Each step starts fresh on its first bar's beat 1: a statement still running there is cut, with no tie, and a Line's pick-ups don't reach back over it. An intro or an ending plays the first grouping. A circled number (③) over a step's first note shows its grouping, the caption names the path, and with the Line off a card a step over the first line shows each grouping the form plays, named the same way, and the path is kept with the chart in this browser and goes in a share link. Your rhythm…, Runs and Cards keep theirs. One path plays at a time: choosing a Groups list sets Gears back to One.
Gears: From the Everything interface, a unit or Your rhythm… on the Changes can change its pulse as the tune goes, after Jerry Bergonzi's gears (Inside Improvisation Vol. 4, chs. 22–26): the same cells, played faster or slower. In Line options, Gears is One (the rhythm's own pulse), Up the gears (quarter-note triplets, 8ths, triplets, 16ths, sextuplets: Bergonzi's five), Down the gears (the same, from sextuplets) or Your list… (pulses as Your rhythm… spells them, 8 8t 16, separated by spaces). It takes the same Step as Groups, and choosing a Gears list sets Groups back to One, so one path plays at a time. Each step starts fresh, as in mixed phrasing. The pulse's name in italics (Triplets) over a step's first note shows where it changes, after the circled number when the grouping changes too. Contraction and expansion (ch. 26) is a gear path by 2 bars: Your list… 8 8t 16, Every 2 bars, say, squeezes the same unit into less time each step. Runs and Cards keep their pulse.
Feel: From the Everything interface, Feel in Line options groups the Changes' beats in 4, in 2 (half time) or in 1, after Jerry Bergonzi's feels (Inside Improvisation Vol. 4, ch. 30) and Hal Galper's half time. In 2 the slashes are half notes (a dotted half in 3/4, a dotted half and a half in 5/4) and 8ths beam by the group; the strong beats stay on 1 and 3. In 1 a slash, and a beam, is the bar long, tied where it's longer than a whole note, and beat 1 is the only strong beat. It changes only how the sheet is written: the rhythm plays the same, and units keep their own beams. It shows with no rhythm, or one that lines up with the beat: a run, a card, or a unit a whole number of beats long (8ths in 2, 16ths in 4). Under a cross-rhythm (8ths in 3) or a Groups or Gears path the rhythm's own grouping leads, so Feel is hidden and the sheet is in 4. It writes "in 2" or "in 1" in italics over the first bar, and "feel in 2" in the caption with a rhythm; it is kept in this browser and goes in a share link. The Scales and Arpeggios sheets keep the beat.
Runs: After Jerry Bergonzi's Inside Improvisation, Vol. 4: Melodic Rhythms (consecutive 8ths, pp. 29–50). A run is a few attacks in a row, the same in every bar. Attacks says how many (2 to 7) and From where in the bar the first one lands, by the count: 1, the and of 1, 2, and so on. A run that reaches past the barline finishes in the next bar. Cards are the simplest per-bar rhythms: Downbeats, Upbeats and Half notes.
Your rhythm…: Type your own. Start with the pulse, 4:, 8:, 8t: or 16:, then one character for each pulse: x plays, . rests, _ holds the note before it, and > before an x accents it. Spaces and | are ignored. 8: >xx.x_ is an accented attack, one more, a rest, an attack held a pulse more. It repeats like a unit. If it doesn't fit these rules the control says so and plays Off.
Rhythm on a Line: With a Line on, the Line's notes are poured into the rhythm: one note an attack, rests skipped, a tie holding the note before it. A chord with more notes than attacks is cut off at its end. With fewer, its line goes on to the next cell or turns back, its notes at the Line's own spacing (Scale steps, below). Poured Lines print one line fewer per page.
Scale steps: A Line's notes keep their own spacing: 7th Chords a half-beat apart, Cells, Pentatonic, Triad pair, Quartal and Upper structure a quarter-beat. A faster rhythm's extra attacks walk the chord's scale (the one the Scales toggle shows) stepwise from each of the Line's notes to the next, and where the steps don't fit, a chromatic passing tone or an enclosure leads into the next note, as a bebop line does: 7th Chords in 16ths is the arpeggio with the scale between its tones. After a chord's last note the line steps on toward the next chord's first. An Approach still replaces the chord's last notes with its figure.
Start: In the Line's options (Everything interface), Start is On the beat or a 1-, 2- or 3-note pick-up. It follows Hal Galper's Forward Motion: From Bach to Bebop (pp. 169–172). Each chord's target, its first note on a beat, is struck even where the rhythm rests, and so is each pick-up note before it. The pick-up's notes are the chord before's; after a rest they are the scale's notes just below the target, and a note outside your range rests. The sheet's first bar has no pick-up, and a 2nd ending starts on its beat.
Timing: Also Everything. Timing begins each chord's notes early (Anticipate) or late (Resolve late), after Jerry Bergonzi's Inside Improvisation, Vol. 4: Melodic Rhythms (p. 119). The chord symbols stay put.
Play in rhythm: In the Line's options (Intermediate), shown with Guide Tones. Guide Tones hold each chord's note unless Play in rhythm is on, which strikes it on the chord's first attack of the rhythm (and on the first in each bar of a chord held longer), and walks the chord's scale on its other attacks, out and back and then by step into the next chord's guide tone, as a player would: the rhythm decides where the line lands (Upbeats: on the "and"). Below Everything, choosing a rhythm under Guide Tones turns it on, so the rhythm reaches the line; turn it off to hold the notes again. Add an Approach and every note a half note or longer gives its last eighths to it, leading into the note after (Half notes with an enclosure: a quarter and two eighths into each half note); in a faster rhythm the chord's last attacks play it into the next chord's guide tone, or its last notes where it has more than they can take, the guide tone keeping its own, and none where its note would repeat the one before. A practice path: hold the guide tones, then land them in a rhythm, then lead into them. Nothing repeats, so Guide Tones take any rhythm, and so does every other Line: a faster rhythm fills with scale steps.
Strong beats: The strong beats of a bar: 1 in 2/4 and 3/4, 1 and 3 in 4/4, 1 and 4 in 5/4 and 6/4, 1 and 5 in 7/4 (in 2, the same; in 1, beat 1 alone). After Hal Galper's Forward Motion: From Bach to Bebop (pp. 47–49, 67): a line releases on the on-beats and builds tension on the off-beats, so it sounds strongest with a chord tone on each strong beat, which Chord tones on strong beats plays.
Chord tones on strong beats: In Line options, for any Line: the Line plays a chord tone on each bar's strong beats (1 and 3 in 4/4; see Strong beats), so you hear the chord land where the line releases (Galper). A note on a strong beat that isn't a chord tone moves to the nearest one, and a note held through one (a guide tone's dotted half, say) is struck again there; on a guide tone line with an Approach, the chord's 7th and 3rd by turns, each led into by the figure (where). Under a rhythm the rhythm keeps its attacks, so only the notes it strikes on a strong beat move. With Anticipate or Resolve late, a strong beat on a chord change moves with the change: the note that lands the new chord early or late plays its chord tone. Under 7th Chords with no Approach every note is a chord tone already, so the toggle is hidden there.
Rhythm card: On the Scales sheet, the Rhythm group puts a card under each staff: the rhythm as slashes on one line, with its accents, triplets and Saindon's bracket. The staff says which notes and the card says when; the whole notes stay as they are, so play the scale in the card's rhythm. The card is one cycle long, the bars it takes to come back on one, up to four bars. A longer cycle ends in … and carries on the same way. A bar is a quarter of the staff's width. The staff and its card take the time signature of the bar that holds the staff's first chord (4/4 where the chart has none), shown on both. The page's subtitle names the rhythm. A sheet with cards prints eight staves a page.
Notes per bar: Beside the Rhythm on the Scales sheet, Notes per bar rewrites each staff as a run, after Jerry Bergonzi's Inside Improvisation Vol. 4 (ch. 1): the scale up from its first note to the octave above and back down, in bars of that many notes (a seven-note scale is 15 notes). The bars are even: a note the bar long for 1; one value for all of them where it fits the bar (four quarters in 4/4, two dotted quarters in 3/4); otherwise a tuplet of the longest value that fits, such as five quarters in the time of four. The last bar's spare notes rest. With a Rhythm too, each bar plays the rhythm's first notes up to that many, and rests the rest, so the rhythm keeps its own values and accents. Practice lights a note each time the run plays it, and the intervals follow the run. The time signature is the staff's, as for the rhythm card, and the page's subtitle names the number. Whole notes is the staff as it was. A sheet with runs prints eight staves a page.
Rhythm on the Arpeggios: On the Arpeggios sheet, the Rhythm group pours each arpeggio into the rhythm: the same notes in the same order, each note an attack, in bars with the time signature (the staff's, as for the rhythm card). Rests and ties come from the rhythm, its beams replace the arpeggio's, and its accents and triplets draw; Saindon's bracket doesn't. The last note's bar rests after it. The page's subtitle names the rhythm, and a sheet with a rhythm prints eleven staves a page. Triad pairs' Block plays chords, so it takes no rhythm and the group hides there.
Grouping: To play an arpeggio grouped in 3, 4, 5, 6 or 7, choose the Rhythm 8ths in N, with accents: every 8th plays, beamed in groups of N across the barlines, the first of each group accented. Grouping in N is that rhythm, after Ed Saindon's Rhythmic Patterns (p. 12) and Jerry Bergonzi's Inside Improvisation Vol. 4 (ch. 32).

How much shows

Interface: How many controls show.Intermediate, where every browser starts: the sheet, instrument, transposing, printing, sharing and editing chords, bars and sections, with the scale level, the analysis rows, lines, scale spelling, Practice, repeats and endings, choosing a chord's scale, and a short list of ready-made rhythms without accents, and an Accents toggle that puts a unit's back (under Guide Tones, the subdivisions alone, Quarters, 8ths, Triplets and 16ths, and the cards: the walk makes the line and the accents are yours). Everything adds every rhythm and its options (grouping, variation, runs, your own), pentatonics, chord picks, functions and key changes, and the chart's source. A sheet set up with controls you can't see says so above it, with Show controls and Reset. For now Everything is hidden while the lines and rhythms of Intermediate are worked on: a browser that chose it opens at Intermediate, and a sheet set up with its controls offers Reset.
Bars per line: In ⋯ More actions on the Changes sheet: Auto (four on a wide screen and in print, two on a phone), 2, 4 or 8. It's the most a line holds: a line too dense to read, 16ths for one, still splits in two even halves, and the rest of its section splits with it, so a section keeps one length of line (the first line alone may split for its clef and key signature). A phone keeps two. There's no 3, which would break a section's four-bar phrases.

Practicing with a click

Click: The note icon beside Print shows a metronome along the bottom of the window (in focus mode, in the bar at the top), so you can play the tune from the sheet without another app. It's set to the chart's time signature, with a tempo and a feel read from its style (how). Start plays it, and Space starts and stops it from anywhere on the page. − and + change the tempo by one (with Shift, by five), as do the arrow keys in the tempo, or type it, 40 to 300; Tap takes it from a few taps of the beat. The feel is what plays between the beats: Quarters, the beats alone; Swing, the skip note of swung eighths; or Straight, even eighths. Under ⋯, what plays, by the sheet. On the Scales, Arpeggios and Patterns, Metronome, the click alone: a count-in of one or two bars; Click on, the beats it sounds (every beat, 2 and 4, 1 and 3, 3 only, 4 only, or the and of 2 and 4, after Bergonzi; how it starts); a hat on 2 and 4 in 4/4; the Swing dial; the sound: Wood or Beep, synthesized, or Stick, a recorded drumstick (a sound file on this site, loaded when you start; until it loads, or if it can't, Wood plays). On the Changes, Comping, the band: the count-in, the Swing dial, Change Tempo and Change Key, the comping style, and the Mix, with your Line and rhythm. The chevron folds it to Start and the tempo, playing on, to leave a phone's screen to the music. The chart remembers its tempo, feel and Click on. A chart that changes time signature partway plays the one it starts in. On an iPhone or iPad it plays on with the screen locked, the song shown in Now Playing, whose Pause and Play stop and start it.
Hearing the Line: With a Line on the Changes sheet, the click's ⋯, Comping, lists Line in the Mix: unmute it and the band plays it with you, the notes on the sheet, in their rhythm, at concert pitch (where), in the form's order, repeats, endings and D.S. too (how), then from the top again. With the click on Swing, its 8ths swing, as far as the Swing dial under the click's ⋯ says (how). It starts muted. Listen first, then play it with the sound, then mute it and play it alone. With a rhythm on the sheet, Click Track in the Mix taps it on a rim with the band, with the Line or without one (what it taps); mute it to leave it out. On the other sheets the click plays alone.
Follow along: With the click running, the Changes sheet shows the bar you're in, washed amber, and in a bar with two chords the one sounding; the page scrolls to keep that line in view, in focus mode too. Your own scrolling wins: the page holds off for a second after it, and while a popover is open (when).
Loop: Loop, at the top of the click's settings: Off, Section (pick one) or Bars… (From and To, the bar numbers the sheet prints). The click, the band and the lit bar go round those bars as the form plays them; the sheet washes them blue and names the loop above its first line, with a ✕. Change it while playing and it takes effect at the next bar. Between rounds puts a bar or two of click alone before each round. Both are remembered with the tempo per chart (what a loop plays).
Play a staff: On the Scales and Arpeggios sheets, the Play button by each staff's label sounds it at the click's tempo: a scale up and down (with Practice on, only the notes you picked), an arpeggio as drawn (how). On the Changes sheet, each pentatonic on a label's ladder has one too: it plays that minor pentatonic up to its octave and back. With the click running it comes in on the next bar. Press it again to stop. Both play a recorded piano, a set of sound files on this site, loaded the first time you play and kept for offline use; until it loads, or if it can't, a plain synthesized tone plays instead. Nothing is recorded or sent.
Metronome and Comping: The sheet decides what plays. On the Scales, Arpeggios and Patterns, Metronome: the click plays alone. On the Changes, Comping: a band plays the chart's changes: piano, bass and drums in the chart's groove (below), the click only counting in. Where no groove plays, the piano holds each chord's voicing, the tensions as the sheet's scales have them at its level, over a bass on the roots (how). A transposed chart plays in its new key. To leave a part out, mute it in the Mix at the bottom of the click's ⋯. Practice over them, with your Line or without it.
Groove: On the Changes a chart's band plays its style's groove. A swing style's Swing groove: the piano comps, the bass walks, the drums play a ride and hi-hat (how). A ballad's Ballad groove: a held piano, a bass in two, a soft ride and cross-stick (how). A bossa or Latin style's Bossa groove: a syncopated piano, a bossa bass, a cross-stick (how). A samba's Samba groove: the kick leaning on 3 like a surdo, the ride or the tamborim's figure on the cross-stick by the tempo, a bass pushing into 3 (how). A partido alto's Partido alto groove: one two-bar figure in all three parts (how); a section can name its own groove (how). A baião's Baião groove: the triangle on the hi-hat, the zabumba's 1 and the and of 2 in the kick and the bass, nothing on 3 (how). An afoxé's Afoxé groove: a true 4/4, 16ths on the hi-hat, the kick and the bass on 2 and 4 and their ands (how). A choro's Choro groove: light, the pandeiro (thumb, tips, heel, tips), a melodic bass on each chord's own bass note (how). A frevo's Frevo groove and a marcha-rancho's Marcha-rancho groove: the frevo phrase on the snare, fast, or slow on brushes (how, how). The click goes quiet after its count-in: the drummer keeps time. The style also sets how far the 8ths swing (how). The drums are recorded too, loaded the first time.
Band: Under the click's ⋯, Comping, with a swing or a ballad chart's groove, Band chooses the rhythm section from a record: Red Garland, Paul Chambers and Philly Joe Jones (Miles Davis Quintet), Bud Powell, Curly Russell and Max Roach, Bill Evans, Scott LaFaro and Paul Motian, Count Basie, Walter Page and Jo Jones, Wynton Kelly, Paul Chambers and Jimmy Cobb, Horace Silver, Gene Taylor and Art Blakey, Erroll Garner, Eddie Calhoun and Denzil Best, McCoy Tyner, Jimmy Garrison and Elvin Jones, or Herbie Hancock, Ron Carter and Tony Williams (Hancock's style from Levine's voicings: no transcription read). Open In the style of under it: Piano, Bass and Drums each choose a player, so any pianist can play with any bassist and any drummer: a player from another band makes the band Your own. Each player's tooltip says what that player's style plays. Each row has its sound's level and Mute; each pianist leaves out as many bars as he would. In playback only (the sheet keeps your Line and rhythm); the band is yours, not in a link. Swing and the Ballad each keep a band of their own, the Ballad starting from your Swing band: under the Ballad each player plays his ballad way, softer, the piano holding its chords, most bassists in two. A ballad in double time plays the Swing groove, and your Swing band with it. A bossa chart plays a band of its own, Antônio Carlos Jobim, Sebastião Neto and Milton Banana (Getz/Gilberto, 1964), and a samba chart the Rio 65 Trio, Dom Salvador, Sérgio Barrozo and Edison Machado: named under Band with each player's level and Mute, but not swapped, and never offered under Swing or the Ballad. On a Brazilian chart Band lists all eight Brazilian bands, the style's own first: pick one and its groove plays (a bossa as a choro, say), at its tempo until you set your own; the chart remembers it. Remembered in this browser. How it decides says what each plays.
Mix: Under the click's ⋯, Comping, each sound playing (the Line, the rhythm, the piano, the bass, the drums) has a level and a Mute. A muted part keeps its level and settings for when it's back. Remembered in this browser.
Change Key and Change Tempo: With the Changes sheet, under the click's ⋯, Metronome: Change Key plays each time through the form in the next key, by 4ths (up a 4th, round the cycle) or by 1/2 step (up a half step), so twelve choruses visit every key; the Line, the piano and the bass move, the drums and the click don't. The sheet follows: as each chorus starts, its chords, guide tones, scales and numerals show in that key (to edit, pin or pick, Stop: the chart itself stays in its written key, and Stop shows it again). The bar says how far the chorus is from the written key, never more than a tritone. Change Tempo plays each chorus 2, 4 or 8 beats a minute faster; Stop puts the tempo back.

Practice: improvise with fewer notes

On the Scales sheet, the Practice panel lets you pick a handful of notes from each scale. Those stay bold and the rest fade back, on screen and in print. Improvising with just the guide tones through a tune is harder (and more useful) than it sounds. The panel's How it works opens a short reminder of what the boxes and presets do.

Presets (in From root) work chord by chord: Chord tones, Guide tones (3rds and 7ths) and Tensions (everything else). They know an altered chord's ♭3 is really a ♯9, so they won't light it as a 3rd.
The boxes pick notes by interval: tick ♭3 and every minor 3rd lights up. They count from the chord's root, not the scale's first note, so with C minor pentatonic over B♭–7, B♭ is 1 and C is 2 (the 9th). The interval labels under the notes show the same numbers. In From C mode the boxes are pitches instead (tick E♭ and every E♭ lights up), which shows you where a note survives a chord change and where it doesn't.
Pentatonic lights a minor pentatonic over each scale: the notes they share, and the pentatonic's others added to the staff in a second color. Built on picks the degree of each chord it starts from: on 2 over Cmaj7 is Dm pentatonic, and over G7 it's Am. Auto picks the one that shares the most, nearest the chord's root (how). The caption under each chord names it and counts the notes it shares (Dm pent · 5 shared). Wholly inside: over a major chord (Ionian) on 2, 3 or 6; over a minor (Dorian) on 1, 2 or 5; over a dominant (Mixolydian) on 2, 5 or 6.
Hexatonic lights two triads from each scale, six notes, after Gary Campbell's Triad Pairs for Jazz. Pairn is the triads on degrees n and n + 1 of each staff's scale; on a seven-note scale that leaves out degree n − 1 (Pair 1 leaves out the 7th). Pair 5 over C major is G/Am, without the F. Auto picks the pair that covers the most chord tones (how); ranked against Key, each staff takes its key area's IV and V triads where its scale holds them, and the caption says off key where it doesn't. The grouping splits the six notes in two (the two triads, chord tones and color, a pentatonic and one more, or the lowest three and highest three), tinted apart; the caption under each chord names the pair.
Quartal lights a stack of fourths from each seven-note scale: its notes three steps apart, Built on the degree you choose, three or four Notes. Auto picks the stack that holds the guide tones without an avoid note (how): F B E A over G7. A stack may hold one augmented fourth; Perfect only allows none. The caption names the stack (D G C F · 4ths).
Click a chord's pentatonic or triad pair (Changes) or a staff's caption (Scales) to pick another for that chord; the list runs from inside to outside. A pick on the Scales sheet sets every bar that staff covers. Default undoes it; ⋯ More actions → Reset chord picks undoes them all. Picks are the same on both sheets, survive a change of Built on or Pair, and go with a share link.
Tick or untick a box while a preset's on and you get your own mix, starting from what the preset showed.
Clear turns it all off.
Your ticks are remembered for each library chart, in this browser, separately for From root and from a note.

Editing a chart

You can change anything in a chart: a reharmonization, a different scale choice, a bridge you play differently. Press Edit, next to the title, and the chart opens as bars, four to a line, always in concert pitch; Done puts it away. The sheet keeps up as you go, and ⌘Z (Ctrl+Z off a Mac) undoes.

The bars

Pick a chord and type to replace it. Space adds a second chord to the bar, Tab and the arrow keys move on, % repeats the bar before, and ⌫ clears it.
Beside the bars, the chord's scales: the usual choice first, then the others that fit, then an Outside group for when you want some tension to resolve. Type in the search box for any scale at all. Under them, its function (a Roman numeral such as V7/ii, which tells the rules what the chord does; Functions and rules shows the scale each gives) and why I chose that scale.
The bar's own buttons add a bar before or after, delete it, start a new section or a key change there, and add endings, a segno, a coda or a jump.
At the end of a section's last line, + bar adds a bar. Under the sheet, Section adds a section after the last and Repeat a section… repeats one; a bar's menu holds Paste bars…. While you edit, every chord shows its numeral and scale.
If a chord comes up amber, I don't recognize it. Pick a scale for it and it'll draw (what happens to it until then).
With the editor open, you can also tap a chord on the Changes sheet to change it there. On a phone that's the way to edit: the bars need a bigger screen.

The source

Under the ⋯ menu, Show source opens the chart as plain text, the same chart as the bars (edit either), and lists anything I can't make sense of under it, with the line number. Chart format has every line it reads, with an example.

Transposing

Transpose…, beside Edit, moves the whole chart to another key, so you can work on a tune in all twelve. It spells things sensibly for the new key (D♭–7 G♭7 in B♭, not C♯–7 F♯7: why). To undo it, transpose back. That's different from the Instrument setting, which only changes how the sheet is written.

Keyboard shortcuts

Anywhere

Key	What it does
`/`	Goes to the tune search, unless you’re typing in a field.
`⌘Z / Ctrl+Z`	Undoes the last change to the chart. ⇧⌘Z (Ctrl+Shift+Z) redoes it. In a text field, it undoes your typing.
`Space`	Starts and stops the click while it’s shown, unless a button or another control has the focus.
`↑ ↓`	In the click’s tempo field: faster or slower by 1, or by 5 with Shift, as − and + are.

Typing a chord

Key	What it does
`Enter`	Takes the chord, or the suggestion picked below it.
`↑ ↓`	Moves through the suggestions.
`Space`	Takes the chord and starts a second one in the bar.
`Tab / Shift+Tab`	Takes the chord and moves to the next or previous bar.
`→ / ←`	At the end or the start of what you typed: takes the chord and moves to the next or previous chord.
`%`	Typed alone: repeats the bar before.
`Esc`	Leaves the chord as it was.

On a guide tone line

Key	What it does
`← →`	Moves to the previous or next chord with a note, on to the next line.
`Home / End`	Moves to the line’s first or last note.
`↑ ↓`	Moves the chord’s pin a half step up or down, from the note the line plays.
`⇧↑ ⇧↓`	Moves the chord’s pin an octave up or down.
`Backspace / Delete`	Clears the chord’s pin: the default again.
`Enter / Space`	Opens the chord’s note and its moves.
`Esc`	Closes the choices; again, leaves the line.

Saving your work

There are no accounts here, so there's nothing to sign in to. Your work is kept three ways instead, and your scale choices come along every time, because they're part of the chart.

My charts: edits save themselves in this browser a moment after you stop typing. Change a library tune and it becomes your version of it, marked Edited, with Revert to library version if you change your mind. Save as a copy keeps a variation beside it, and New chart starts from scratch. They're all listed at the top of the library.
Versions: when a tune has more than one chart, like Summertime and its Jazz Mind Accelerator version, the Version menu above the sheet switches between them. Your own charts of the tune (a copy, or a chart with its title) are listed there too, under Mine; add a version: line to give yours a name.
Download saves the chart as a plain .txt file you can keep anywhere. Open chart… in the library (or dropping the file on it) brings it back. It also opens an iReal Pro export (.html), and Import iReal link… takes a song or playlist link: the chords come across in concert pitch, and it lists anything it leaves out.
Share makes a link with the whole chart packed inside, plus your instrument, where the scales start, and practice picks. Open it on your phone, or send it to your bandmates. Nothing is uploaded: the chart lives in the link itself.

One catch: My charts lives in this browser only. Another browser or device won't see it, and clearing this site's data wipes it. For anything you'd hate to lose, download it.

Back up and restore

Backup → Back up… in the library saves everything this browser keeps in one file: My charts, each chart's practice picks, level and chord picks (the alternate changes' too, and which set you play), the same for library tunes, and your preferences (instrument, range, theme, how the sheets look). Undo history stays behind, and so does each chart's click tempo. Restore from backup… (or Open chart…, or dropping the file on the library) brings it into another browser. It shows what's new, what's already there and what differs before anything changes; nothing of yours is replaced unless you choose it.

A chart that differs from yours:Keep both unless you choose otherwise. The backup's comes in beside yours with “(imported)” on its title; an edited library tune comes in as a copy, so both show in its Version menu. Use imported replaces yours, its picks with it, and clears its undo history; Keep mine skips it.
A library tune's picks and level: yours are kept unless you choose Use imported.
Preferences: used straight away only in a browser that has never opened this site; anywhere else, only if you tick the box. Reload to see them.

If the browser's storage fills up partway, it stops and says what was restored and what wasn't; each chart comes in whole or not at all. My charts holds at most 200.

Moving from chordscalemaker.com

The site was Chord Scale Maker, at chordscalemaker.com; it's now Two Five One, at 251jazz.com. A browser keeps a site's charts under its address, so the ones you saved there aren't here yet. While that browser holds charts of yours, or picks or a level for a library tune, chordscalemaker.com shows a notice: Move my charts to 251jazz.com opens this site in a new tab and hands it everything a backup would hold, then asks what to do with any that differ from yours, as Restore from backup… does. If the tab doesn't open, or nothing comes across, Back up… there and Restore from backup… here does the same by file. When the notice shows.

Printing and Focus

Print gives you clean letter pages, black on white whatever mode you're in: twelve staves a page for scales, eight lines a page for the changes (fewer with guide tones on). The dashed lines on screen show where each page starts. To get a PDF, pick "Save as PDF" in your browser's print dialog.
Focus hides everything but the sheet music, for practicing from a tablet or laptop on the stand. Its pages are fitted to the screen, so the sheet's labels are plain text there: pick a scale or open a chord's Why before you go in. Press Esc or Exit focus to come back.

Odds and ends

The moon (or sun) at the top right switches between light and dark mode.
The note beside it switches between Real Book notation, the default, and the standard look. Real Book is a handwritten look for the staff, the title and the chord symbols, which take the fake book's shorthand (C–⁷, B♭△⁷, Eø⁷, A7 with its ⁽♭⁹⁾ raised, D with its ⁶⸍⁹ raised). It's only the look: the chords, scales and lines are the same, and a screen reader still reads each symbol as it's spelled out elsewhere. It prints as it shows.
Your settings stay in this browser and nowhere else; there's no account and nothing to sign in to. The privacy page has the details.
Missing a tune? Request a chart in the library takes you to the contact form. Tell me the tune, and if you can, attach a photo or PDF of the changes.
Wondering why the app chose something? How it decides says, for every choice it makes. For one chord's scale, click its numeral or scale on the Changes sheet: the note says why and names the rule, and Functions and rules lists them all. If you'd choose differently, Report issue in that note collects the details for the contact form.
Scales and Chords, in the navbar, have a page for every scale and chord the app plays: its notes, a staff for your instrument, the chords or scales it goes with, and the library tunes that use it. Each starts on C: choose another of the twelve roots above its notes, and the pitch you read in (Concert, B♭, E♭, F or Bass) beside its staff. A link to the page keeps the root. Composers lists the library by composer.
Many library tunes name a notable recording under Recording, below the sheets, and play it on the page; where it can't play there, Listen on YouTube opens it.
What's new? The release notes list every change, newest first.
It works on a phone, but the staves are small. A tablet or a laptop is nicer.
It works offline too. Add it to your home screen (on an iPad or iPhone, Share → Add to Home Screen) and it opens like an app. Once you've opened the site, every tune in the library is there without a connection.