String Quartet No. 6 is the last of six chamber-music works in the string quartet medium by the American composer Milton Babbitt.
Babbitt’s expansive and lyrical Sixth Quartet was written in 1993. It is in two sections, in each of which the work's underlying six-part all-partition array of fifty-eight aggregates is unfolded separately in each of the four instruments. There are only momentary breaks in each part, which otherwise play continuously throughout the work, giving the sense of an endless flow of music, saturated with florid detail. Changes in muting and playing technique, usually in one instrument at a time, are used to mark off composite pitch aggregates (Mead 1997, 117).
The work is based on an all-partition array which is (with a few swapped partitions) the M5 transform of the one used in The Joy of More Sextets (1986), for violin and piano (Colson 2012, 2).