Philip Glass and the Human Unconscious
“One interesting aspect of the music of Philip Glass is that despite its supposed ‘avant-garde’ modernity, it utilizes elements that have been around for over a thousand years. Almost all of Glass’s compositions employ a ground bass, a series of unchanging bass notes upon which are stacked a variety of short melodies and scales. The ground bass evolved out of the ‘cantus firmus’ used in Gregorian Chant and was characteristic in Baroque music.”