John Coolidge Adams (born February 15, 1947) is an American composer, clarinetist, and conductor of classical music and opera, with strong roots in minimalism. His works include Nixon in China (1987), Harmonielehre (1985), Short Ride in a Fast Machine (1986), On the Transmigration of Souls (2002), a choral piece commemorating the victims of the September 11, 2001 attacks (for which he won the Pulitzer Prize for Music in 2003), and Shaker Loops (1978), a minimalist four-movement work for strings.