Harmonic Subdominant and Dominants are chords built by adding extra accidentals that don't exist in the original key. How to find Harmonic Subdominants of a Major Key In a Major key, chord IV , or the triad built on the fourth scale degree, sounds Major. For example in the key of C Major , chord IV is F Major (triad - F,A,C). By turning this triad into MINOR (F,Ab,C) we get what we call a 'harmonic' subdominant. Chord II (i.e. chord built on the second scale degree) is also a subdominant, therefore can also be 'harmonic'. Let's say we take a seventh chord on the second scale degree (chord II7) in C Major. We have the notes D,F,A,C - which sounds like a minor seventh chord. If you alter the A to an Ab, you'll get a D half-diminished seventh chord, which is your harmonic II7! How to find the Harmonic Dominant of a minor Key In a minor key, chord V , or the triad built on the fifth scale degree sounds minor. For example in the key of a minor , chor...