about

Where all of this comes from

There is no dataset behind this site. Every chord, every scale, every key signature, every fingering and every printed exercise is computed from the rules of notation when the site is built — which is a stronger claim than it sounds, and a riskier one.

A site built on a table fails visibly: a row is missing and the page is empty. A site built on a calculation fails invisibly: the page is full, the answer is plausible, and it is wrong on four hundred pages at once. Spell a scale by looking up the nearest name for each pitch instead of walking the letters and G♭ major comes out as G♭ A♭ B♭ B D♭ E♭ F — six notes right, one letter used twice, and nobody notices for a year.

So six things are checked before a build is allowed to publish, and every one of them compares this site against something outside itself:

1. All thirty key signatures are compared against the published figures — C♭ major with seven flats, C♯ major with seven sharps. One accidental out of place anywhere in the spelling engine and this fails.
2. Round trip. Every chord name is turned into notes and the notes are turned back into names, on all 17 roots and all 22 types. The name that comes back has to be the name that went in.
3. The diagrams are read back off the finished page. A test opens a built chord page, reads the fret numbers out of the drawing, converts them to pitches with a function that had nothing to do with drawing them, and checks they are the chord the heading claims.
4. Every bar of every generated exercise is checked by a function that did not build it: the durations add up exactly, nothing is beamed across a beat, every tie joins two notes.
5. Every built page is scanned for NaN, undefined and Infinity, which is what a broken calculation looks like when it reaches a reader.
6. The open chords every guitarist already knows — E, A, D, G, C, Am, Em, Dm — have to be the first fingering the search returns for each of them. If the ranking stops agreeing with what a hand actually does, that is where it shows.

3,658 pages: 1,122 chords (17 roots × 22 types × 3 instruments), 1,119 scales (22 scales and modes), 204 intervals, 30 key signatures, 10 time signatures, 810 reading sheets, 210 rhythm sheets and 128 kinds of blank paper.

Seventeen roots rather than twelve, because C♯ major and D♭ major are the same sound and two different pieces of notation, and somebody looking for one is not served by the other.

• Songs. No tablature, no chord sheets, no repertoire. Those are licensed from publishers by the sites that carry them, and this site has no licence and wants none.
• Grades and syllabuses. The examination boards own their names and their requirements. Nothing here is aligned to any of them and nothing here says it is.
• An account. There is nothing to sign in to. Your scores, your seeds and your theme live in your own browser.
• A consent banner, because there is nothing to consent to: no third-party analytics, no advertising cookie set by us, no tracker. Visits are counted without cookies or identifiers.
• A tenor clef. The key-signature positions this site derives match the printed convention exactly for treble, bass and alto and do not for tenor. Rather than ship a clef whose signatures are a guess, there are three.

A few things on this site are our reading rather than a fact, and they are named where they appear: which notes a chord may drop when an instrument runs out of strings, how hard a fingering is, and the order the chord-naming page puts its candidates in. The last of those is printed under every list it produces, because a list without the rule that made it is an opinion pretending to be a machine.

The difficulty score is the clearest case. It is a weighted sum of fingers, barre, stretch, position, silenced strings and open strings, and the weights are ours. What keeps it honest is not the formula but the test: the eight open chords everyone already plays have to come out first. When a silenced string was cheaper than a finger, the search offered 32000x for G major — fewer fingers, and not the chord anybody plays. The weight moved.