Music Theory Reference

Complete music theory reference for musicians at every level — from foundational scales and chords to intervals, key signatures, and modes. Every concept includes practical context, cross-linked relationships, and frequency data from the Tunable note reference. Use this hub to navigate any area of music theory.

Scales 25 scale types from major and minor to pentatonic, modal, and jazz scales. Every scale includes the interval formula, note names, and diatonic chord qualities in all 12 keys. Chords 20 chord types from basic triads to seventh chords and extended harmony. Note formulas, inversions, harmonic function, and song examples in all 12 roots. Intervals 17 intervals from perfect unison to major thirteenth. Just ratios, ear training melody references, temperament comparison, and note pair examples for every interval. Keys 30 major and minor key signatures organized by the circle of fifths. Key signature display, diatonic chords, relative/parallel key cross-links, and transposing instrument context. Modes 7 church modes — Dorian, Phrygian, Lydian, Mixolydian, Locrian, and beyond. Modal structure, characteristic notes, tonal color, genre context with song examples.

Keys & Circle of Fifths

See all key relationships on the Circle of Fifths — the clockwise/counterclockwise progression through all major and minor keys, enharmonic equivalents, and key signature navigation.

Related References

Practice with Tunable Note Frequencies