Carnegie Hall - Steve Reich @ 70

Sextet is in five movements played without pause. The relationship of the five movements is that of an arch form, A-B-C-B-A. The first and last movements are fast, the second and fourth movements moderate, and the third slow. Changes of tempo are made abruptly at the beginning of new movements by means of metric modulation, to get either slower or faster. Movements are also organized harmonically, with one chord cycle for the first and fifth, another for the second and fourth, and yet another for the third. The harmonies used are largely dominant chords with added tones creating a somewhat darker, chromatic, and more varied harmonic language than in my earlier works. Both the cyclical movement and structure, and the general harmonic language, were suggested by The Desert Music (1984).

Percussion instruments mostly produce sounds of relatively short duration. In this piece, I was interested in overcoming that limitation. The use of the bowed vibraphone was one means of obtaining long sustained sounds not possible with a piano. The mallet instruments (marimba, vibraphone, etc.) are basically instruments of high and middle register without a low range. To overcome this limit, the bass drum was used doubling the piano or synthesizer—particularly in the second, third, and fourth movements.

Compositional techniques used include some introduced in my music as early as Drumming (1971). In particular, the technique of substituting beats for rests to “build up” a canon between two or more identical instruments playing the same repeating pattern is used extensively in the first and last movements. Another is the sudden change of rhythmic position (or phase) of one voice in an overall repeating contrapuntal web first occurs in my Six Pianos (1973) and is used throughout this work. Double canons, where one canon moves slowly (the bowed vibraphones) and the second moves quickly (the pianos), first appear in my music in Octet (1979). Techniques influenced by African music—where the basic ambiguity in meters of 12 beats is between three groups of four and four groups of three—appear in the third and fifth movements. Another more recent technique appears near the end of the fourth movement, in which the melodic material played by one pair of instruments (the synthesizers) is gradually removed, leaving the accompaniment played by another pair (the vibraphones) to become the new melodic focus. Similarly, the accompaniment in the piano in the second movement becomes the melody for the synthesizers in the fourth movement. The ambiguity here is between which is melody and which is accompaniment. In music that uses a great deal of repetition, I believe it is precisely these kinds of ambiguities that give vitality and life.

—Steve Reich