In C :: Therry Riley 1964
Riley’s In C is a composition with a set of instructions rather than a score per se; a semi-aleatoric musical piece composed in1964 for any number of people, (35 is desired if possible).
It consists of 53 short, numbered musical phrases; each phrase may be repeated an arbitrary number of times. Each musician has control over which phrase he or she plays: players are encouraged to play the phrases starting at different times, even if they are playing the same phrase. The phrases must be played in order, although some may be skipped. As detailed in some editions of the score, it is customary for one musician (“traditionally… a beautiful girl,” Riley notes in the score ) to play the note C in repeated eight notes. This functions as a metronome and is referred to as “The Pulse”.