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Tomus

Music theory, explained in the order it makes sense

Eight topics, 52 lessons, connected so you can follow a thread rather than land on a stray page. Start anywhere — each page links to what it depends on.

Practise this in Tomus
  1. 01

    Foundations

    The ideas everything else assumes you already have.

    • Pitch and the musical alphabet
    • Semitones and tones
    • Octaves and register
    • The staff
    • Ledger lines and middle C
    • Enharmonic notes
    Open topic
  2. 02

    Notes and note reading

    Reading pitch off the page — clefs, staff positions and accidentals.

    • Treble clef notes
    • Bass clef notes
    • Sharps, flats and naturals
    • Alto and tenor clefs
    Open topic
  3. 03

    Rhythm

    Duration and pulse — note values, rests, bars and time signatures.

    • Beat, rhythm and tempo
    • Note values and rests
    • Dotted notes and ties
    • Time signatures
    • Triplets and tuplets
    • Syncopation
    Open topic
  4. 04

    Intervals

    The distance between two notes, and the building block for everything else.

    • What is an interval?
    • Major and minor intervals
    • Perfect intervals
    • Augmented and diminished intervals
    • Interval inversion
    • Compound intervals
    Open topic
  5. 05

    Scales

    Ordered sets of notes built from fixed interval patterns.

    • Scale degrees
    • The major scale
    • Minor scales
    • The modes
    • Pentatonic scales
    • The chromatic scale
    Open topic
  6. 06

    Keys and key signatures

    The home note of a piece, and the sharps or flats that come with it.

    • Key vs scale
    • Key signatures
    • Relative and parallel keys
    • Transposition
    • How to find the key of a song
    Open topic
  7. 07

    The circle of fifths

    The map that arranges all twelve keys by how closely related they are.

    • How to use the circle of fifths
    Open topic
  8. 08

    Chords

    Notes stacked in thirds — quality, inversions and how chords sit in a key.

    • Triads
    • Major vs minor chords
    • Chord inversions
    • Seventh chords
    • Chord symbols
    • Suspended chords
    Open topic
  9. 09

    Harmony

    What chords do once they are in a key — and why some orders sound finished and others do not.

    • Diatonic chords
    • Roman numerals
    • Harmonic function
    • Cadences
    • Chord progressions
    • Modulation
    • Secondary dominants
    • Borrowed chords and modal mixture
    Open topic
  10. 10

    Ear training

    Hearing what you can already read — intervals, chords and pitch.

    • Relative pitch vs perfect pitch
    • Interval ear training
    • Chord ear training
    • Melodic dictation
    Open topic

Suggested paths

If you would rather be told where to start.

Reading music

  1. 1.Treble clef notes
  2. 2.Bass clef notes
  3. 3.Note values
  4. 4.Time signatures

Understanding harmony

  1. 1.What is an interval
  2. 2.Major vs minor chords
  3. 3.Chord inversions

Keys and scales

  1. 1.The major scale
  2. 2.Minor scales
  3. 3.Key signatures
  4. 4.The circle of fifths