1. A Harmony Tester comprising means for analyzing chords of notes according to the pitch of said notes to determine the semiton s separating said notes; determining intervals separating said notes according to said semitones and according to accidental preference and current key and scale mode; identifying chord degrees, species, modes and inversions by comparing said intervals and semitones with a plurality of chord structures; determining intervals and semitones of progression of voices from chord to successive chord and determining intervals and semitones of progression of passing notes and their allies; and testing said chords and progressions for compliance with a plurality of classical rules of harmony.