*Augmented octave and diminished unison on C = C♯. Equal-tempered: 21/12:1 = 100 cents. MIDI pitch bend: none Note how the diminished unison is essentially equivalent to the augmented unison.
C major and E minor contrast through their respective notes C and B (in red and orange), each a half step apart or leading tones. The chords share two notes (in blue) however.