Section 11 from Gestures II (1958-1962), for two pianos, performed as percussion instruments from inside the piano (rather than from the keyboard).  In the recorded musical example the pianists are Robert Ashley and Gordon Mumma.  The score page is read from left to right, with the time indications in 15 second intervals.   

The physical placement and approximate time of the sounds are indicated separately for each pianist.  The sound resonances result from the dampers being raised throughout the section. The traditional 5-line stave notation at the left side of the page is a connection from the previous section, and is not heard on this recording.

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Section "x" from Gestures II (1958-1962), for two pianos.  There are two recorded examples: the first with pianists Robert Ashley and Gordon Mumma (in a 1962 live performance), the second with pianists David Tudor and Gordon Mumma (from a 1969 recording session).  The section # of "x" indicates that the piece can be played anywhere between the other 11 sections of Gestures II, whenever the pianists choose to do so.

The single score page includes parts for both pianists, in a "game form" of distinct musical phrases".  Each pianist may start at any phrase.  The phrases follow the horizontal (or slightly diagonal) "ligature" lines, either to the arrow at the end of each line, or switch from one staff to another where the vertical lines intersect.  When each pianist ends a phrase at an arrow, a pause is required. (Pauses are also indicated by a comma.)  

Conceptually there are 14 "basic" phrases.  But to complicate the "game" aspect,  one pianist may choose to coordinate specific pitches with the other pianist, at the places (in time) where vertical lines in the score connect with pitches on another staff.  And as a further "game-level" complication, at that pitch and point in time the pianist may choose to switch from one phrase to another.

The solid (black) notes are short and rapidly articulated.  The open notes are sustained; the duration is the choice of the performer.  Section "x" begins when one of the pianists begins, and the other pianist must then begin.

The duration of section "x" is entirely the choice of the pianists:  At the end of a phrase one pianist makes a "conclusion gesture" and the other pianist ends with the conclusion of their phrase. If all possibilities of this "phrase switching" with "pitch-time matching" were to be notated in traditional 5-line staves, the score would consume well into 100 pages.

Thus, this single-page of musical score for two pianists is an encoding of a possibly very long composition, though it is sometimes performed as short as 6 seconds duration as in the performance here with Robert Ashley and Gordon Mumma. The performance with David Tudor and Gordon Mumma is about 20 seconds

Hear an MP3 sample of this piece with Robert Ashely

Hear an MP3 sample of this piece with David Tudor