Not surprisingly music changed dramatically between the years 600 and 1600. Perhaps the two most notable developments are the invention of musical notation and development of polyphony. Music was one of the branches of the quadrivium. While the nature of music in Western Europe underwent radical change, there were a number of remarkably long lived concepts. The theories of Guido of Arezzo were still being taught in the seventeenth century, and Pythagorean tuning still held sway until Bach's Well Tempered Clavier.
Music in the Church
Despite numerous references to music in the Bible, the early Roman church was wary of music, associating it with wild, lacivious pagan celebrations. As a compromise it was agreed that singing could be performed in church, but without musical instruments. The term a capella derives from this practice of unaccompanied singing.