Tetrachord Construction Kit — Build Any Scale From Two Four-Note Groups

Pick two tetrachords, build a scale, rotate through its modes, and harmonize in thirds, triads, or tetrads. 65 scales from two building blocks.

What is a tetrachord?

A tetrachord is a group of four notes — usually written as three intervals between them. The major tetrachord (whole-whole-half) is the first four notes of a major scale. The minor tetrachord (whole-half-whole) is the first four of a natural minor scale. There are only a handful of common tetrachord patterns, and every scale you’ll ever play is built from two of them stacked.

Why this matters

Once you can name a few tetrachord patterns, you can construct almost any scale without memorizing it. Dorian? Two minor tetrachords. Melodic minor? Minor on the bottom, major on top. Harmonic minor? Minor on the bottom, harmonic on top. Every “exotic” scale is just an unfamiliar pairing.

Read more

• Tetrachords — Learn 4 Patterns, Build Every Scale and Mode — the theory behind how tetrachord combinations work
• Modes Without the Mystique — the Musician Basics chapter that walks through every mode
• Your First Chords — start here if “tetrachord” is a new word

Learn it live

The Musician Basics & Ear Training class covers tetrachords, modes, and scale construction as a live cohort on Discord. Small groups, direct feedback, weekly sessions.