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The shared foundation

Music theory,
from first principles.

The shared foundation. Notes, intervals, scales, chords — the theory every instrument depends on. No prior knowledge assumed, no sheet music required. Work through it once, and it underpins every instrument you'll ever pick up — bouzouki, guitar, voice, or anything else.

Start chapter 1 →

Three parts, twenty chapters

  1. I

    Foundations of sound

    Pitch, the musical alphabet, the octave, and the 12 notes that everything else is built from.

    6 chapters · 1 interactive

  2. II

    Intervals & scales

    How notes combine into intervals, how intervals build scales, and how Roman numerals let us talk about either in any key.

    8 chapters · 2 interactive

  3. III

    Chords

    Where chords come from — stacking thirds on a scale — and how the seven triads of every key fall out of one simple rule.

    6 chapters · 1 interactive