The transformation from Ionian to Lydian mode theory posits that a single accidental alteration—specifically raising the perfect fourth scale degree by a semitone—fundamentally restructures harmonic and melodic functions within tonal music systems. This mechanism creates distinct chord qualities, such as transforming supertonic minor triads into major triads and altering dominant function via diminished seventh chords in Lydian b7 contexts, thereby modifying tendency tones and secondary key center resolutions. The concept belongs to the domain of Western Music Theory, specifically modality, defining how scalar modification dictates harmonic progression dynamics without requiring a full modulation or change of tonal center terminology.
The transformation from Ionian to Lydian mode theory posits that a single accidental alteration—specifically raising the perfect fourth scale degree by a semitone—fundamentally restructures harmonic …