Chord diagrams whose fingerings are found by searching the fretboard, so the notes under the dots really are the chord's. Ten tunings, sixteen qualities, and the notes named on the page.
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Trace a PNG or JPG into real SVG paths, with holes that stay holes and transparency that is not read as black. The page counts the pixels its own vector differs from the picture, and at the exact setting that count is zero.
Pack frames into a sheet with an atlas that names each sprite's own rectangle, or slice a sheet back apart with margin and spacing read off the pixels. The page checks every frame comes back out of the sheet byte for byte.
Transcribe audio into sheet music in your browser: the Basic Pitch neural network finds the notes in humming, singing, solo instruments, piano or a full song, then the tool tracks the beat through rubato, detects the meter (4/4, 3/4, 6/8, 12/8) and the downbeat, writes triplets and chord symbols, names the key, and engraves the result with tuplets, ties and a metronome mark; a song comes out as a piano arrangement, the tune over its bass line. A piano roll drawn on the tracked beats lets you remove or move notes; every setting re-computes instantly without re-running the model. Exports MusicXML (with tuplets, ties and harmony), MIDI, SVG, PNG, and PDF or print on Letter or A4 paper with whole lines of music on every page.
Every shape the shipped library carried, scored by the tuning and the fret arithmetic: a string is a known note and a fret is a semitone.
Input
39 stored shapes · guitar E2 A2 D3 G3 B3 E4, ukulele G4 C4 E4 A4, bass E1 A1 D2 G2
Shapes that sound the chord they name
before after guitar 19 / 19 searched ukulele 6 / 6 searched bass 4 / 14 searched all three 29 / 39 320 / 320 bass "E" 0220 sounds E B E G, which is E minor bass "F" 1331 sounds F C F Ab, which is F minor bass "B" 2442 sounds F# C# F# A, and no B at all
The guitar and ukulele tables were already right, which is worth recording. Ten of the fourteen bass shapes were not: they sounded a different chord from the one printed above them. The answer is not to correct a table but to stop keeping one, so the fingerings are now found by searching every string and fret and keeping only the shapes whose pitch classes ARE the chord’s.
Chord diagrams whose fingerings are found by searching the fretboard rather than looked up in a table, so the notes under the dots really are the chord’s. Ten tunings, sixteen qualities, and the page names every note it draws and says which is the root, the third and the fifth.
Draw a diagram for a lesson and know the notes under the dots are the ones you are teaching.
Ask for a chord in DADGAD or open G and get shapes that really sound it.
Enter a fingering you found somewhere and read back exactly what it sounds.
The first shape offered is x32010, which sounds C3, E3, G3, C4 and E4. The panel names each one, calls C3 the root and E3 the major third, and says the shape is root position because the lowest note is the root.
Type E, then click the fretboard to place a dot at the third fret of the fourth string. The panel says: this is not E, it does not sound the G sharp, and it sounds an A sharp, which E does not contain.
Choose DADGAD and ask for Dsus4. The search finds shapes on a tuning no built-in library carried, and every one of them is checked before it is shown.
A chord diagram is a claim about notes: this dot on this string at this fret is that pitch. The claim is arithmetic, because a string is tuned to a known note and a fret is a semitone. A guitar’s sixth string is E2, MIDI 40, so stopped at fret 3 it is G2. That makes "is this the chord it says it is" a question with an exact answer, and the answer settled two things about the version this replaces.
**The guitar and ukulele shapes were already right.** All nineteen guitar shapes and all six ukulele ones sound the chord they name, which is worth recording rather than assuming. **The bass shapes were not: ten of the fourteen do not contain the notes their name claims.** The shape printed under "E" was 0220, which sounds E, B and G, and that is E MINOR. "F" was 1331, which sounds F, C and A flat, F minor. "B" was 2442, which sounds F sharp, C sharp and A: F sharp minor, with no B in it anywhere. "G" was 3000, G, A and D, with no third at all. "Am" was 0020, E, A and G, with no C. And "G5" was one note, where a power chord is a root and a fifth.
The answer is not to correct a table by hand but to stop keeping one. Every shape here is FOUND, by walking every string and every fret in a twelve-fret window and keeping the combinations whose pitch classes are the chord’s. That means it cannot be wrong in the way a typed table can, it works for any chord name rather than the twenty that happened to be entered, and it works on any tuning: standard guitar, drop D, DADGAD, open G, ukulele in both the reentrant and low-G tunings, four and five string bass, banjo and mandolin. The test suite drives 320 offered shapes across five tunings and recomputes every note from the tuning independently; not one sounds a note its chord does not contain.
The shapes are ordered by how easy they are to hold, and the ordering is a real model rather than a preference: the stretch between the lowest and highest fretted fret, whether a barre is needed, how many fingers are down, how far up the neck it sits, how many strings are muted, and whether the lowest sounding note is the root. That ordering puts the shape a player already knows first: x32010 for C, 320003 for G, xx0232 for D, x02210 for A minor, 022000 for E minor. Interior mutes are excluded rather than penalised, because a muted string between two ringing ones is rarely what anyone means.
The page then says what it drew. Every sounding note is named in scientific pitch notation with its degree (root, major third, fifth, minor seventh), the lowest note is named and the diagram is called root position or an inversion, a missing tone is named as a note rather than as a fault code, and a note the chord does not contain is named too. Sixteen qualities are offered, from major and minor through suspensions and power chords to half diminished, diminished sevenths, added ninths and dominant ninths, and the six that this project’s sheet-music code also defines are checked against it for all twelve roots.
Clicking the fretboard builds your own shape, and it goes through exactly the same check, so a diagram you have drawn from memory can be verified rather than trusted. Export is SVG with its namespace declared, or PNG rendered at three times the diagram size.
They are searched, not stored. Every string may be muted, open or stopped anywhere in a twelve-fret window, and the shapes kept are the ones whose pitch classes are the chord’s. That is why any chord name works on any of the ten tunings.
Ten of the fourteen bass shapes did not sound the chord they named. The one under "E" sounded E minor, the one under "F" sounded F minor, and the one under "B" sounded F sharp minor and contained no B at all. The guitar and ukulele shapes were all correct.
Because the fifth is the note a seventh chord gives up when a hand runs out of fingers, and that is a real voicing rather than a mistake. The page says which tone was left out and that the quality allows it.
With "String names" on they are the open strings. With "Note under each string" on they are the notes that shape actually sounds, in scientific pitch notation, so middle C reads as C4.
Yes. Click the fretboard to place and remove dots and the panel scores what you built against the chord name, naming any note that is missing and any note that does not belong.
The stretch between the lowest and highest fretted fret, whether a barre is needed, how many fingers are down, how far up the neck the shape sits, how many strings are muted, and whether the lowest sounding note is the root.
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