In the liberal arts, the trivium was concerned with language (grammar, rhetoric, dialectic), the quadrivium with the mathematical arts (arithmetic, geometry, astronomy). And music was included with the latter.

Boethius (c. 480-525) collected and recorded ideas about music in his day in De Institutione musica (The Fundamentals of Music). Music is divided into three types:

• musica mundane -- the music of the spheres and cosmic harmony among the stars, planets, seasons, elements, etc. The music of the spheres is unheard because of the lack of sensitivity in human ears. Interestingly, some years ago, scientists discovered that a black hole in the universe was emitting a sound -- a particular note.
• musica humana -- the union of body and soul. The beauty of anatomical harmony plus the relationships to the soul is analogous to musical order and symmetry.
• musica instrumentalis -- audible music including that of the voice as an "instrument."