2026-07-072026-07-07http://salesiana.dossiersoluciones.com/handle/123456789/114166Using the residue class rings we analyze the structure of sequences of musical intervals for the all-interval tone-semitone series and the quart modes as well. The relations we stated show the enharmonic return of the series to the initial point.8 pagesRings and Algebras13A99text