Chance music (leaving one or more aspect of the music up to random chance) is known to have existed in some form since Mozart, who is said to have used dice to determine the order of measures and musical phrases in some of his works. The genre really emerged and broadened during the 1900’s, however, when John Cage pioneered music that uses chance throughout the whole work. Music of Changes (for solo piano) is one of Cage’s earlier works in which he used the I Ching to compose the piece.
When composing this work, Cage wrote parts of the music such as melodies and chords, then he used the I Ching to arrange what he had written. After he had arranged the notes and had an overall sound concept, Cage restarted and used the I Ching to assign note durations, tempos, dynamics, and other musical elements.
Undergraduate music majors commonly study this piece in their music history and theory classes because it is one of the most randomized pieces in the literature. It brings about the question of whether or not it is music: there are no coherent melodic or harmonic lines, and a toddler could probably bang out something similar if seated in front of a piano. The composition style and intent behind it, however, is what makes it art. Cage predetermined notes and harmonies, then intentionally and methodically randomized and organized them. The piece might make a better talking point than listening experience, but it is interesting to know that it is out there.
Music of Changes (1951) by John Cage