Read the circle
Moving clockwise takes you up a perfect fifth: C, G, D, A, E and onward. Moving counterclockwise takes you up a perfect fourth. The outer ring selects major keys; the inner ring selects their relative minor keys. C major and A minor share the same notes, but each gives a different note the role of tonic.
Follow a key into its chords
In C major, the seven triads are C, Dm, Em, F, G, Am and B diminished. Choose a degree below the circle to hear it. Try C, F and G, then return to C. Switch to the relative minor to compare the same collection of notes around A. The minor view uses natural minor; it does not automatically raise the seventh as harmonic minor does.
Move beyond the key
A selected chord stays in place when you change the reference key, making comparisons possible. Continue with the negative harmony or tritone substitution guides to explore other ways to develop a chord. The displays use twelve pitch classes; sharp and flat equivalents occupy the same position.