Twelve keys on a wheel, each one a fifth from the next. Neighbours share almost everything; keys across the wheel share almost nothing. Click chords into a loop, hear it, and watch the path you drew explain why some steps feel like coming home and others like a leap.
cooking · work in progressMajors on the outside, their relative minors inside. The shaded wedges are the chords that live in the home key, with their Roman numerals. Click any wedge to add that chord and hear it; the seven numerals below the wheel do the same. The path is your loop.
Two things make a chord change feel smooth or sudden: how far round the wheel it travels, and how many notes the two chords share. They are not the same measure. A leap across the wheel keeps none of the three, every time. But one wedge is not reliably close: a step round the ring keeps one note, a step inward to the relative minor keeps two, and a step from a minor wedge out to the next major keeps nothing at all. That is why the table counts the notes instead of leaving you to read them off the picture.
The wheel. Start at C and go up a fifth twelve times and you come back to C, having visited every key once. Laid out as a circle, each key sits between the two keys it shares the most with: G major has every note of C major but one. That is why a song can drift one wedge round and barely notice, and why jumping across the wheel sounds like a door opening onto a different room.
Home. Pick a key and seven chords are built from its seven notes, one on each. The numerals are the chord's address inside the key, so the same loop can be played from any home: I, V, vi, IV is the same shape wherever you start. Capital numerals are major chords, small are minor, and the little circle marks the odd one out, the diminished chord on the seventh note, which almost nobody uses as a resting place.
Pull. Some chords are content to sit; some lean towards a neighbour. The fifth chord, V, leans hardest towards home, because its notes sit a semitone below the home note and want to slide up into it. The readout above the table says where convention usually goes next from the chord you ended on. It is a habit of hundreds of years of songs, not a law, and every good song breaks it somewhere on purpose.
The four chords. I, V, vi, IV has carried a remarkable share of the pop charts. Play it and look at the path: no step moves more than one wedge, and it ends on IV, which convention is content to send back to I. Two of its three changes keep a note. The third, V to vi, drops all three at once, and that is the step that lifts. A loop designed to be repeated, which is exactly what it was for.
Triads only, no sevenths, so the jazz turnaround sounds plainer than it should. A chord can be sent an octave up or down, marked with a chevron on its step and on the path. One voice for every chord, a soft sound with a few harmonics from the sound tile, and the notes of each chord chosen to move as little as possible from the chord before, which is the easiest rule of voice leading and not the whole of it. No melody, no rhythm beyond a chord every few beats, and no minor-key subtleties beyond the borrowed V that every minor-key song uses.
The next-chord habits are stated for major and minor keys as most theory books state them. They describe common practice in Western popular and classical music and nothing else; a great deal of music does not work this way at all. Counts, does not judge: a leap is a leap, not a mistake.
Everything is made in this tab. No samples, no model, nothing leaves the page.