Score The score of
In C consists of 53 "modules" that fit on a single page. Each module is a short musical phrase notated in
treble clef without a
time signature and bracketed by
repeat signs. Riley uses nine different
pitch classes, only omitting C/D, D#/E, and G/A from the
chromatic scale. The total duration of the written score is only 521
eighth notes. The shortest module lasts one eighth note, and the longest lasts 64. The material varies widely in character, from drones to running
sixteenth note figures. Three of the modules are repeated: Nos. 10 (as 41), 11 (as 36), and 18 (as 28). The longest figure is #35, which spans 60 pulses, ranges an octave and a half, and includes seven different pitches. Its length creates a sense of figure 35 as a turning point in the piece, creating a symmetry or even hinting at a very loose
ternary form.
Instructions There are a few rules for performing
In C that have remained since its first performance. They primarily define the
indeterminate nature of the piece: •
Instrumentation: The piece can be played by any group of musicians on any type of instrument. •
Tempo: There is no required tempo. All performers play at the same pace. •
Patterns: The 53 patterns are to be played in order. •
Repetitions: Individual players determine how often to repeat any pattern. •
Transposition: Patterns may be transposed up or down by octaves. •
Coordination: An eighth note pulse may be used to coordinate the performance. It can be played on the top two octaves of a piano or mallet percussion instrument. Time can also be kept by improvised percussion. •
Ending: The piece ends when all players arrive at pattern 53. Performers stop playing individually. Though they are governed by the same tempo, the musicians are not required to play together. Performers are encouraged to stagger their entrances, which creates a
heterophonic canon. Riley diagrammed the 12th module in several alignments to demonstrate how freely the musicians can perform the score. He initially asked players to remain within 4–5 modules of each other. However, much of its structure is specifically designed to reduce the scope of chance. Riley conceived of a version where each pattern lasted a week and the final pattern was played in the new year. The most recent set of instructions from 2005 differs significantly from Riley's original notes. However, Riley's first instructions hint at some leeway: "The pulse is traditionally played by a beautiful girl on the top two octaves of a grand piano. She must play loudly and keep a strict tempo for the entire ensemble to follow." The 2005 version of the score explicitly makes the pulse optional: "The ensemble can be aided by the means of an eighth note pulse played on the high C's of a piano or mallet instrument." After decades of familiarity with
In C, Riley came to feel that "any good musicians now could keep it together...I don't like The Pulse, as is sometimes used, 'out in front,' where it becomes very annoying. That wasn't my intention of the piece at all." At the piece's 20th anniversary performance in
Hartford, Connecticut, no pulse was used. ==1968 recording==