Charles Peter Wuorinen ( /ˈwɔːrɪnən/, Finnish: [ˈʋuorinen]; June 9, 1938 – March 11, 2020) was an American composer of contemporary classical music based in New York City. He also performed as a pianist and conductor. Wuorinen composed more than 270 works: orchestral music, chamber music, solo instrumental and vocal works, and operas, such as Brokeback Mountain (2014). His work was termed serialist but he came to disparage that idea as meaningless. Time's Encomium, his only purely electronic piece, received the 1970 Pulitzer Prize. Wuorinen taught at several institutions, including Columbia University, Rutgers University and the Manhattan School of Music.

Wuorinen was born on the Upper West Side of Manhattan in New York City. His father, John H. Wuorinen, the chair of the history department at Columbia University, was a noted scholar of Scandinavian affairs, who also worked for the Office of Strategic Services, and wrote five books on his native Finland. His mother, Alfhild Kalijarvi, received her M.A. in biology from Smith College. Wuorinen excelled academically, graduating from Trinity School (New York City) as valedictorian in 1956; he later received a B.A. (1961) and an M.A. (1963) in music from Columbia University. Early supporters included Jacques Barzun and Edgard Varèse.

Wuorinen began composing at age 5 and began piano lessons at 6. At 16 he was awarded the New York Philharmonic's Young Composers' Award and the John Harms Chorus premiered his choral work O Filii et Filiae at Town Hall on May 2, 1954. He was active as a singer and pianist with the choruses at the Church of the Heavenly Rest and the Church of the Transfiguration (Little Church Around the Corner), and was the rehearsal pianist for the world premiere of Carlos Chávez's opera Panfilo and Lauretta at Columbia University during the spring of 1957. From 1952 to 1956 Wuorinen was president of the Trinity School Glee Club. He was pianist, librarian, and general manager of the Columbia University Orchestra in 1956–57. During the summers of 1955 and 1956, he was the organist at Saint Paul's Church in Gardner, Massachusetts, where his parents stayed during the summer months. He was awarded the Bearns Prize three times, the BMI Student Composers Award four times, and the Lili Boulanger Award twice (1961 and 1962). He was a fellow at the Chamber Music Conference and Composers' Forum of the East for several years. Many early professional performances of Wuorinen's compositions took place on the Music of Our Time series at the 92nd Street Y run by violinist Max Pollikoff.

In 1962 Wuorinen and fellow composer-performer Harvey Sollberger formed The Group for Contemporary Music. The ensemble raised the standard of new music performance in New York, championing such composers as Milton Babbitt, Elliott Carter and Stefan Wolpe, who wrote several works for the ensemble. Many of Wuorinen's works were premiered by The Group, including Chamber Concerto for Cello and the Chamber Concerto for Flute. Major Wuorinen compositions of the '60s include Orchestral and Electronic Exchanges, premiered by the New York Philharmonic conducted by Lukas Foss; the First Piano Concerto, with composer as soloist; the String Trio, written for the then newly formed new music ensemble Speculum Musicae; and Time's Encomium, Wuorinen's only purely electronic piece, composed using the RCA Synthesizer at the Columbia-Princeton Electronic Music Center on a commission from Nonesuch Records, for which Wuorinen was awarded the 1970 Pulitzer Prize for Music at the age of 32. Wuorinen was appointed to instructor at Columbia in 1964 and promoted to assistant professor in 1969, the year he received an Ingram Merrill Foundation grant; during this period, he was visiting lecturer at the New England Conservatory (1968–71), Princeton University (1969–71), the University of Iowa (1970), and the University of South Florida (1971).

The 1970s were a particularly fruitful period for Wuorinen, who taught at the Manhattan School of Music from 1971 to 1979. Chamber works during this decade include his first two string quartets, the Six Pieces for Violin and Piano, Fast Fantasy for cello and piano, and two large works for the Tashi Ensemble, Tashi and Fortune. Works for orchestra include Grand Bamboula for strings, A Reliquary for Igor Stravinsky, which incorporates the elder master's last sketches, the Second Piano Concerto, and the Concerto for Amplified Violin and Orchestra, which caused a scandal at its premiere at the Tanglewood Festival with Paul Zukofsky and the BSO conducted by Michael Tilson Thomas. In 1976 Wuorinen completed his Percussion Symphony, a five-movement work for 24 players including two pianos for the New Jersey Percussion Ensemble and his longtime colleague Raymond Des Roches, as well as his opera subtitled "a baroque burlesque", The W. of Babylon with an original libretto by Renaud Charles Bruce. The New Jersey Percussion Ensemble had also performed and recorded Wuorinen's composition "Ringing Changes" in collaboration with the Group for Contemporary Music prior to the Percussion Symphony, setting the stage for this challenging larger-scale work. The ensemble, created by Raymond Des Roches, recorded the Percussion Symphony, which was released in 1978 by Nonesuch. In the late 1970s Wuorinen became interested in the work of the mathematician Benoit Mandelbrot and with a grant from the Rockefeller Foundation he conducted sonic experiments at Bell Labs in New Jersey. In an interview with Richard Burbank, Wuorinen is quoted as saying:

What I did at Bell Labs (with Mark Liberman) was to try various experiments in which strings of pseudo-random material, usually pitches but sometimes other things, were generated and then subjected to traditional types of compositional organization, including twelve-tone procedures. What I wanted to do was to see whether or not these things sounded "composed," sounded purposively chosen. They did, at least by my lights. The random sequences were not just any old random sequences but were that of a kind called 1/f randomness.

The 1980s were framed by two large-scale works for chorus and orchestra based on Biblical texts, the 60-minute oratorio The Celestial Sphere for the 100th Anniversary of the Handel Oratorio Society in Rock Island Illinois of 1980 and Genesis (1989), jointly commissioned by the Minnesota Orchestra and San Francisco Symphony. Other major orchestral works during this period include the Rhapsody for Violin and Orchestra; the Third Piano Concerto, written for pianist Garrick Ohlsson; Movers and Shakers, the first work commissioned by the Cleveland Orchestra for music director Christoph von Dohnányi; Bamboula Squared for computer-generated sound and orchestra (inspired by Wuorinen's work at Bell Labs); and The Golden Dance. Wuorinen was composer in residence with the San Francisco Symphony from 1984 to 1989. Major chamber works of the 1980s include his Third String Quartet commissioned to commemorate the 25th anniversary of the Hopkins Center for the Arts at Dartmouth College, The Blue Bamboula for pianist Ursula Oppens, the Sonata for Violin and Piano commissioned by the Library of Congress and premiered at the Library on an all-Wuorinen concert, String Sextet, New York Notes, Third Piano Sonata for Alan Feinberg, and trios for various combinations including three works for horn trio. In the 1980s Wuorinen began an association with the New York City Ballet which resulted in a series of works designed for dance: Five (Concerto for Amplified Cello and Orchestra) for choreographer Jean-Pierre Bonnefoux and Wuorinen's longtime colleague and champion Fred Sherry, Delight of the Muses based on works of Mozart and commissioned in honor of the Mozart's bicentennial, and three works inspired by scenes from Dante's La Divina Commedia for Peter Martins (The Mission of Virgil, The Great Procession and The River of Light). In addition to the Dante texts Wuorinen was influenced by the watercolors of William Blake. For the New York City Ballet Wuorinen also made a two-piano arrangement of Schoenberg's Variations for Orchestra (Schoenberg) choreographed by Richard Tanner, and Martins created a ballet based on Wuorinen's A Reliquary for Igor Stravinsky. In 1985 Wuorinen was awarded a MacArthur Foundation Fellowship.

Wuorinen devoted increased attention to writing works for voice, including his setting of Dylan Thomas's A Winter's Tale for soprano Phyllis Bryn-Julson and the Fenton Songs I & II on poems by British poet James Fenton, with whom Wuorinen was collaborating on an opera. Major chamber works included the Saxophone Quartet for the Raschèr Saxophone Quartet, Percussion Quartet, Piano Quintet, and Sonata for Guitar and Piano. Orchestral works included the Concerto for Saxophone Quartet and Orchestra and Symphony Seven as well as the Dante works for the New York City Ballet.