Music theory

A workbench, not a lesson. Pick a key and the keyboard and fretboard fill in; build a chord and watch where it sits inside that key; chain chords into a progression and hear it loop. The colours are scale degrees — the same ones the song pages use, so a shape you learn here is the shape you will recognise there.

C major

1 2 3 4 5 6 7 — the reference every other scale is described against

In your library: 25 songs in C major →

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1 · fundamental2nd3rd4th5th6th7th

C1D2E3F4G5A6B7

Chords in C major

Built by stacking every other note of the scale. These are the chords that belong to the key — click one to see and hear it, + to put it in the progression.

Build a chord

Any chord, in or out of the key. Notes that do not belong to the current scale come up in cyan on the diagrams — that is how a borrowed chord announces itself.

triads

sevenths

extensions

CCEG

Progression

One bar per chord, looping. While it plays, the notes shared with the previous chord hold steady and the voices that moved pulse — that handful of moving notes is what makes a progression sound like it is going somewhere. The count on a shape is how many songs in your library loop on it.

Nothing yet — add chords with + above, or load one of the shapes.

Modes

Seven ways to hear one scale. Every row below uses exactly the same notes as C major — all that changes is which note you treat as home, and that changes everything about how it feels. The mode on each degree is the scale that fits the chord built on that degree, which is why they sit side by side here.

IC Ionianyou are hereover C1 2 3 4 5 6 7the major scale itself
iiD Dorianover Dm1 2 ♭3 4 5 6 ♭7♭3 ♭7 against major
iiiE Phrygianover Em1 ♭2 ♭3 4 5 ♭6 ♭7♭2 ♭3 ♭6 ♭7 against major
IVF Lydianover F1 2 3 ♯4 5 6 7♯4 against major
VG Mixolydianover G1 2 3 4 5 6 ♭7♭7 against major
viA Aeolianover Am1 2 ♭3 4 5 ♭6 ♭7♭3 ♭6 ♭7 against major
vii°B Locrianover B°1 ♭2 ♭3 4 ♭5 ♭6 ♭7♭2 ♭3 ♭5 ♭6 ♭7 against major

The accidentals in the right-hand column are the whole difference. Lydian is major with one note raised; Mixolydian is major with one note lowered. ▸ vs major plays plain major and then the mode from the same note, and flashes exactly what moved — that is the characteristic sound.

Train your ear

The boards show; this asks. Everything is played in C, so what you are learning is the relationship, not a fixed note.

One of the key's seven chords — which numeral?

Circle of fifths & fourths

Every key, arranged so that neighbours are the most closely related. Click any segment to load it above.

C major — no sharps or flatsCG major — one sharpGD major — two sharpsDA major — three sharpsAE major — four sharpsEB major — five sharpsBG♭ major — six flatsG♭D♭ major — five flatsD♭A♭ major — four flatsA♭E♭ major — three flatsE♭B♭ major — two flatsB♭F major — one flatFA minor — relative minor of C, no sharps or flatsAmE minor — relative minor of G, one sharpEmB minor — relative minor of D, two sharpsBmF♯ minor — relative minor of A, three sharpsF♯mC♯ minor — relative minor of E, four sharpsC♯mG♯ minor — relative minor of B, five sharpsG♯mE♭ minor — relative minor of G♭, six flatsE♭mB♭ minor — relative minor of D♭, five flatsB♭mF minor — relative minor of A♭, four flatsFmC minor — relative minor of E♭, three flatsCmG minor — relative minor of B♭, two flatsGmD minor — relative minor of F, one flatDmCno sharps or flatsrelative: Am

↻ clockwise — up a fifth↺ anticlockwise — up a fourth

  • the key you are in
  • one step clockwise — its V, the chord that pulls home
  • one step anticlockwise — its IV
  • inner ring — the relative minor, the same notes from a different home

Neighbours differ by one accidental, which is why moving between them sounds smooth and why IV and V are the chords progressions lean on hardest. Opposite sides of the wheel share almost nothing — that is the sound of a jarring key change.

Everything here is derived from the twelve notes; the song links are where your library already uses it. Browse the library →