Hamlisch collapsed and died Monday after a brief illness, his publicist Ken Sunshine said, citing the family. Other details were not released.
Hamlisch's career included composing, conducting and arranging music from Broadway to Hollywood, from symphonies to R&B hits. He won every major award in his career, including three Academy Awards, four Emmys, four Grammys, a Tony and three Golden Globes.
The one-time child prodigy's music colored some of Hollywood and Broadway's most important works.
Hamlisch composed more than 40 film scores, including "Sophie's Choice," ''Ordinary People," ''The Way We Were" and "Take the Money and Run." He won his third Oscar for his adaptation of Scott Joplin's music for "The Sting." His latest work came for Steven Soderbergh's "The Informant!"
On Broadway, Hamlisch received both a Tony and the Pulitzer Prize in 1976 for the long-running favorite "A Chorus Line" and wrote the music for "The Goodbye Girl" and "Sweet Smell of Success." He was scheduled to fly to Nashville, Tenn., this week to see a production of his musical "The Nutty Professor," Sunshine said.
Hamlisch even reached into the pop world, writing the No. 1 R&B hit "Break It to Me Gently" with Carole Bayer Sager for Aretha Franklin. He won the 1974 Grammys for best new artist and song of the year, "The Way We Were," performed by Barbra Streisand.
"He was classic and one of a kind," Franklin said Tuesday after learning of his death, calling him one of the "all time great" arrangers and producers. "Who will ever forget 'The Way We Were'?"
Hamlisch's interest in music started early. At the age of 7 he entered the Juilliard School of Music, stunning the admissions committee with his renditions of "Goodnight Irene" in any key they desired.
In his autobiography, "The Way I Was," Hamlisch admitted that he lived in fear of not meeting his father's expectations. "By the time Gershwin was your age, he was dead," the Viennese-born musician would tell his son. "And he'd written a concerto. Where's your concerto, Marvin?"
In his teens, he switched from piano recitals to songwriting. Show music held a special fascination for him. Hamlisch's first important job in the theater was as rehearsal pianist for the Broadway production of "Funny Girl" with Streisand in 1964. He graduated to other shows like "Fade Out-Fade In," ''Golden Rainbow" and "Henry, Sweet Henry," and other jobs like arranging dance and vocal music.
"Maybe I'm old-fashioned," he told The Associated Press in 1986. "But I remember the beauty and thrill of being moved by Broadway musicals - particularly the endings of shows. The end of 'West Side Story,' where audiences cried their eyes out. The last few chords of 'My Fair Lady.' Just great."
Although he was one of the youngest students ever at Juilliard, he never studied conducting. "I remember somebody told me, 'Earn while you learn,'" he told The AP in 1996.
"The Way We Were" exemplified Hamlisch's old-fashioned appeal - it was a big, sentimental movie ballad that brought huge success in the rock era. He was extremely versatile, able to write for stage and screen, for soundtracks ranging from Woody Allen comedies to a somber drama like "Ordinary People."
He was perhaps even better known for his work adapting Joplin on "The Sting." In the mid-'70s, it seemed everybody with a piano had the sheet music to "The Entertainer," the movie's theme song. To this day, it's blasted by ice cream trucks.
Hamlisch's place in popular culture reached beyond his music. Known for his nerdy look, complete with thick eyeglasses, that image was sealed on NBC's "Saturday Night Live" during Gilda Radner's "Nerd" sketches. Radner, playing Lisa Loopner, would swoon over Hamlisch.
Hamlisch was principal pops conductor for symphony orchestras in Pittsburgh, Milwaukee, Dallas, Pasadena, Seattle and San Diego at the time of his death. He was to be announced to the same position with the Philadelphia Orchestra and also was due to lead the New York Philharmonic during its upcoming New Year's Eve concert.
He was working on a new musical, "Gotta Dance," at the time of his death and was scheduled to write the score for a new film on Liberace, "Behind the Candelabra."
He leaves behind a legacy in film and music that transcended notes on the page. As illustrative as the scenes playing out in front of the music, his scores helped define some of Hollywood's most iconic works.
He is survived by his wife of 25 years, Terre.