4, also known by its other title Buczak, is a string quartet by the American composer Philip Glass.
[1] It was commissioned by Geoffrey Hendricks in remembrance of the artist Brian Buczak, who succumbed to AIDS-related complications in 1987 at the age of 33.
[2] It was premiered at a memorial service on the second anniversary of the artist's death on July 4, 1989 at the Hauser Gallery.
Glass wanted his fourth quartet to represent "a musical impression of [Buczak] as a person as well as a tribute to his life's work".
[4] The first movement begins with unison and then develops to freely interchanged melodic and rhythmic components.