Final answer:
The statement that by the 1500s, the use of three-voice parts became common is true, reflecting the evolving musical practices of the Renaissance period, particularly seen in the popularity of the madrigal.
Step-by-step explanation:
By the 1500s, the use of three-voice parts in music indeed became common. This is a true statement. During the Renaissance, composers began exploring richer textures in vocal music, which led to the widespread use of three-voice parts. The era saw the advent of the Italian madrigal, a secular form of music that often incorporated this three-part vocal structure, featuring two higher voices in canon over an instrumental accompaniment.
This evolution in musical composition reflected a departure from the exclusively open-fifths and octaves commonly used in the earlier Medieval period where the interval of the third was considered a dissonance. By the Renaissance, however, composers were regarding thirds as consonant intervals, leading to smoother and more harmonically rich polyphony, as well as encouraging the use of larger ensembles.