"With those two gods of art, Apollo and Dionysus, we link our recognition that in the Greek world there exists a huge contrast, in origins and purposes, between visual (plastic) arts, the Apollonian, and the non-visual art of music, the Dionysian. Both very different drives go hand in hand, for the most part in open conflict with each other and simultaneously provoking each other all the time to new and more powerful offspring, in order to perpetuate for themselves the contest of opposites which the common word 'Art' only seems to bridge, until they finally, through a marvelous metaphysical act, seem to pair up with each other and, as this pair, produce Attic tragedy, just as much a Dionysian as an Apollonian work of art."
"In order to get closer to these two instinctual drives, let us think of them next as the separate artistic worlds of dreams and of intoxication, physiological phenomena between which we can observe an opposition corresponding to the one between the Apollonian and the Dionysian."
(Friedrich Nietzsche, excerpt from The Birth of Tragedy)