Tonalité grégorienne: Musica recta as Prescriptive Harmony
Late nineteenth-century organist-composers wrote liturgical music dans la tonalité grégorienne based on Niedermeyer and d'Ortigue's chant-accompaniment treatise Traité théorique et pratique de l'accompagnement du plain-chant (1857). The resulting music contained no musica ficta —, especially not raised leading tones in minor—a watershed moment in the nineteenth-century re-emergence of diatonic modality. Focusing on modes 1 and 2 (the Dorian modes) as a case study, part 1 of the essay discusses the historical background of Niedermeyer's treatise, part 2 examines features and theoretical implications therein, part 3 details large modal collections such as Guilmant's Soixante interludes dans la tonalité grégorienne, and part 4 analyses two Dorian marches: one from Guilmant's L'Organiste pratique and one from Gigout's Cent pièces brèves dans la tonalité du plain-chant.