Circle of fifths

Choose a key or click a sector. The outer ring shows major keys, the inner ring their relative minor keys. Both scales share a key signature. Starting from C, clockwise adds sharps and counterclockwise adds flats.

B/Cb, F#/Gb and C#/Db are enharmonic pairs: they sound alike in equal temperament but use different spellings and signatures. Select either spelling in the key menu; the number on the circle follows your choice.

Results show the major and natural minor scales and the seven diatonic major-key triads. Roman numerals indicate scale degrees; lowercase denotes minor, ° diminished. Harmonic and melodic minor are not shown. International note names use B for German H and Bb for German B.

Use Tab to focus a sector, arrow keys to move around the circle and Enter or Space to select.

C major is selected initially. Click a diatonic chord to hear its root-position triad in equal temperament (A4=440 Hz); this does not play a minor-key harmonization. Stop, changing key and leaving the tool end all voices. No sound starts automatically. Arrow keys move the single keyboard focus; Home/End reach the first/last sector. Enter or Space selects it. A selected enharmonic spelling is preserved when its sector is selected again. Only the key choice is kept locally; results and playback are not saved.