Lewis & Short

mŏdŭlātĭo, ōnis, f. [modulor], a regular measure (post-Aug.).

  1. I. In gen.: operis modulationes, Vitr. 5, 9, 3: dorica, id. 5, 9, 2: incedendi, a marching to time, Gell. 1, 11, 18.
  2. II. In partic., a rhythmical measure, modulation; hence, singing and playing, melody, in poetry and music, Quint. 9, 4, 139: modulatione produci aut corripi (verba), id. 9, 4, 89: modulatio pedum, id. 1, 6, 2: scenica, id. 11, 3, 57: vocis, melody, id. 11, 3, 59: musica, Aus. Ep. 25, 13.