Circle of fifths, harmonic waves, and music theory
C Major
Visualize music theory relationships. The circle of fifths shows keys separated by perfect fifths — neighbors share six of seven notes. Chord tones light up on the piano keyboard and on the circle. Harmonic waves show the standing wave ratios: a perfect fifth (3:2) beats barely; a minor second (16:15) beats fast, sounding dissonant. Press Play to hear chords via Web Audio API.