Progression, MUSICAL. The regular succession of chords or the movement of the parts of a musical composition in harmony, where the key continues unchanged, is called Progression; where a new key is introduced it is not progression, but Modulation (q.v.).
Progression, MUSICAL.
Chambers's Encyclopaedia, Volume 8: Peasant to Eoumelia, p. 437–438
Source scan(s): p. 0446, p. 0447