Harmony reference

Diatonic Harmony

Diatonic harmony organises chords from the notes of a particular diatonic scale or key. It connects scale degrees with recurring chord qualities and harmonic relationships.

Developing reference

Overview

A harmony is diatonic when its notes belong primarily to the current seven-note collection. This creates a shared pitch vocabulary among its chords without requiring every chord to serve the same function.

Building Diatonic Chords

Triads can be formed by selecting alternating scale degrees above each note of the scale; adding another alternating degree produces diatonic seventh chords. The resulting qualities depend on the interval pattern of the parent collection.

Scale Degrees and Relationships

Numbering chords by scale degree makes their positions transposable between keys. Those numerals identify location within the collection, while functional interpretation describes how chords behave in a particular phrase.

Applications

Diatonic harmony supports chord-progressions analysis, songwriting, harmonisation, transposition, ear training, and modal comparison. Chromatic chords can then be understood as additions to, or departures from, that shared collection.