Ambrose, St. c340-397. Bishop of Milan. Introduced Plainsong (chant) into church music.

Gregory I, St. Benedictine Pope 590-604. Developed Plainsong, Gregorian chant. Sent Augustine to Canterbury.

Medieval Music. 476-13C. Church oriented. Evolved from Plainsong to polyphonic.

Plainsong. Gregorian chant. Singing in unison without harmony.