The theory of diatonic harmony originated in 1722 from Jean-Philippe Rameau’s Treatise on Harmony. Rameau was the first to argue that music consisted of harmonies built from chords (triads) and their inversions. He also asserted the Perfect Authentic Cadence (V-I) “suffices to justify all rules in music.”

His theories form the framework of diatonic tonality we use today, which has expanded to include chord extensions, alterations, and substitutions. But, the basis for harmony remains the same – triads, inversions, and harmonic movement.

Today, diatonic harmony consists of chords that move and resolve regardless of their traditional function. Saxophone players imply harmonic movement through leading tones. 

The challenge for musicians who play melodies is forming an aural image of a chord as a whole and not just individual chord tones. 

We will explore ways to develop harmonic imagination and construct chord alterations and substitutions from leading tones.