MusicTheory.Work

Music theory you can hear.

A free course from your very first note to jazz harmony. Every idea is something you can play, see on the staff, and hear — then practise until it sticks.

Start learningExplore the Toolbox

No account needed. Your progress stays on your device.

Play any key

Try three keys at once — like C, E and G.

Click, tap, or use your computer keys A–K. On a phone, try two or three fingers.

Every lesson takes about five minutes, in the same four moves.

  1. 1A short ideaOne concept, explained in a few sentences — no jargon you haven't met yet.
  2. 2Something to playA demo you can touch: the keyboard, the staff, the circle of fifths.
  3. 3PracticeQuick questions you answer by ear, by eye, and by playing — with feedback you can hear.
  4. 4A checkA final question or two. Then the skill joins your review schedule so it sticks.

Tools that outlive the lessons.

The circle of fifths, a chord builder, ear trainers, a progression sandbox, a fretboard for guitar and bass — every demo is also a tool you can open any time. Tap a key on the circle and watch it turn.

Open the Toolbox
CIamviGVemiiiD2♯b°vii°A3♯f♯mE4♯c♯mB= C♭5♯g♯mF♯= G♭6♯d♯mD♭= C♯5♭b♭mA♭4♭fmE♭3♭cmB♭2♭gmFIVdmiiCmajor

Seventeen units, zero to fluent.

Already know some? A short placement test skips what you know — and maps every skill, not just a single score.

Foundations

Sound, rhythm, reading, and your first scale.

  1. 1Sound and pitch — Notes, octaves, the keyboard, half and whole steps.
  2. 2Rhythm — Pulse, note values, time signatures, rests, syncopation.
  3. 3Reading music — Treble and bass clef, the grand staff, ledger lines, accidentals.
  4. 4The major scale — How it's built, why it works on any note, and the names of its degrees.

Building blocks

Intervals, keys, minor scales, and chords.

  1. 5Intervals — Size, quality, inversion, and hearing them.
  2. 6Keys — Key signatures, the circle of fifths, relative and parallel minor.
  3. 7Minor scales — Natural, harmonic, and melodic minor.
  4. 8Triads — Major, minor, diminished, augmented — and inversions.

Harmony

How chords work together, and how lines move.

  1. 9Diatonic harmony — Chords of a key, Roman numerals, and what each chord does.
  2. 10Progressions and cadences — Common progressions, I–IV–V–I, ii–V–I, and how phrases end.
  3. 11Seventh chords — Five types, and the seventh chords in every key.
  4. 12Melody and voice leading — Chord tones, non-chord tones, and four-part writing.

Colour and motion

Modes, chromatic chords, key changes, jazz harmony, and real music.

  1. 13Modes — All seven modes, their characteristic sound, and modal mixture.
  2. 14Secondary dominants — Borrowing dominants to point at other chords.
  3. 15Modulation — Changing key, pivot chords, and closely related keys.
  4. 16Extended and altered harmony — 9ths, 11ths, 13ths, tritone substitution, borrowed chords.
  5. 17Song analysis — Put it all together on real music.