Glass, Philip, 1937-, American composer, b. Baltimore. Considered one of the most innovative of contemporary composers, he was a significant figure in the development of minimalism in music. Glass attended the Juilliard School of Music (M.A., 1962) and studied (1964-66) with Nadia Boulanger in Paris. There he also met Indian musicians Ravi Shankar and Alla Rakha, whose music was to influence his own compositions strongly. In 1968 he formed the Philip Glass Ensemble, a small group that employs electronically amplified instruments. During the 1970s he became known for music that blended standard notation and tonality with electronics. These lengthy and highly rhythmic compositions employ a number of phrases that are repeated and slowly modified during the music's course. The purest form of this style is represented in the four-hour-long Music in 12 Parts (1971-74).

More traditional harmonies entered his work with the opera Einstein on the Beach (1976), which Glass wrote with Robert Wilson; a work introduced the minimalist style to a mass audience and paved the way for a wider acceptance of contemporary opera. The meditative Einstein is without narrative plot and blends light, image, and sound as well as dance, words, and music into a hypnotic whole. During the ensuing years Glass's work has become more complex and varied. His best-known works are his operas; Satyagraha (1980), Akhnaten (1984), The Fall of the House of Usher (1988), Hydrogen Jukebox (1990, a collaboration with Allen Ginsberg), The Voyage (1992), and La Belle et la Běte (1994, composed for Jean Cocteau's film) followed Einstein. Three had their American debuts in 2001—The Marriages between Zones 3, 4 and 5 (1997); the epic White Raven (1998), another collaboration with Robert Wilson; and the smaller-scale In the Penal Colony (2001), based on the Franz Kafka short story. Later operas are Galileo Galilei (2002); Waiting for the Barbarians (2005), based on a novel by J. M. Coetzee; and Appomattox (2007), which dramatizes the American Civil War's last weeks and its aftermath. Glass's other compositions include symphonies, concertos, string quartets, songs, and film scores. Glass's work has been extremely influential in the development of a new generation of composers.