Abstract: Embodiments of the present invention provide a tonal analysis method including the steps of parsing notes of a musical score to generate a time-ordered plurality of sonorities; confirming a plurality of tonal centers each having a tone; accounting a chord of a sonority for a confirmed tonal center to determine whether the chord of the sonority is a functional symbol of the confirmed tonal center; and identifying a tonally stable region of the musical score for a confirmed tonal center, then accounting the chord of each sonority in a tonally stable region as a functional symbol of that tonal center. Embodiments of the present invention provide a non-transitory computer-readable medium which stores the output of the tonal analysis method as sonority data structures associated with theory line entry data structures.