Marvin Hamlisch, who achieved theatre immortality as the composer of the iconic musical A Chorus Line, died Aug. 6 2012 following a brief illness. He was 68.

Mr. Hamlisch's other theatre works included the musicals They're Playing Our Song, Jean Seberg, Smile, The Goodbye Girl and Sweet Smell of Success. He also wrote songs for Nora Ephron's play Imaginary Friends. His latest show, The Nutty Professor, recently opened in Tennessee. But it was with the groundbreaking A Chorus Line—which told of the frustrations and worries of a group of anonymous dancers trying out for a Broadway musical—that he made his mark as a theatre figure.

He was already famous as an all-around wunderkind when he began work on A Chorus Line. A child prodigy, he was accepted into Juilliard at the age of six—the youngest child ever to be welcomed by the august Manhattan institution. His first Broadway job was as rehearsal pianist for Funny Girl starring Barbra Streisand—a professional relationship that would last his entire life. Producer Sam Spiegel hired him to play piano at his parties, where he made connections, leading to his writing his first film score, for "The Swimmer" starring Burt Lancaster. Many more film scores followed.

It seemed his fate to brush up against show-business legends while on his way up the ladder. He wrote songs for Liza Minnelli, worked with Judy Garland and was accompanist and straight man for Groucho Marx during a 1974-75 tour.

Professional acknowledgment came easy in his early years. Before he was 30, he had received three Oscars, for his score and song to "The Way We Were" and his adaptations of Scott Joplin ragtime tunes in "The Sting," which helped usher in a Joplin revival. And that was all in 1973. He began to be a regular guest on talk shows and was called "the best-known movie composer since Henry Mancini."

Mr. Hamlisch is one of only 11 people to have won an Emmy, Grammy, Oscar and Tony award. On top of this, he also won the Pulitzer Prize for A Chorus Line. Aside from director-choreographer Michael Bennett, Mr. Hamlisch was by far the most accomplished and famous artist invited to participate in the creation of A Chorus Line. The unorthodox show—a prime example of what came to be known as the "concept musical"—derived from 30 hours of taped confessions of a group of theatre gypsies and chorines. From these recordings, Bennett shaped a show about the strivings, hopes, dreams and fears of the unsung and uncelebrated members of the theatre community. The show was trail-blazing in eschewing a linear plot, dealing with contemporary issues such as homosexuality and abortion in frank terms, and lacking a single headlining star.

Hamlisch was drafted by Bennett and paired with the fussy, eccentric lyricist Ed Kleban, a former executive at Columbia Records with no previous theatre credits. It was an odd couple pairing if there ever was one, but it produced a timeless result. The score was episodic, with each song telling the life story of one or more characters. The show included two modern classics: the hopeful "What I Did for Love," which Kleban and Mr. Hamlisch reportedly wrote under protest, as they considered it a commercial "sell-out" number; and "One," the show's finale. It's throbbing, hop-step opening vamp is one of the best known theatre anthems in musical history, and is known to millions.

Marvin Hamlisch was born June 2, 1944, into a musical family. His father Max Hamlisch was an accordionist and band leader. He began playing piano when he was five. "I started studying music at the age of five and a half," he remembered later. "My older sister was taking piano lessons. When her teacher left our apartment, I would get up on the piano bench and start picking out the notes that were part of my sister's lessons." His song "Sunshine, Lollipops and Rainbows," written while he was a teenager, was a hit for Lesley Gore in 1963.

He followed up A Chorus Line with another hit, though one of a far smaller scale. They're Playing Our Song had lyrics by Carole Bayer Sager and a book by Neil Simon. The two-character musical was based on the real-life relationship between Hamlisch and Sager, and follows the two mismatched songwriters—he is focused and all business, she is flightily and distracted—as they go through a series of bumps in forging both a professional and romantic relationship. After a tryout in Los Angeles, it ran for two-and-a-half years on Broadway and was nominated for a Tony Award for Best Musical.

Mr. Hamlisch's untrammeled string of successes during the 1970s were such that he had a hard time following them up. The next 30 years of his career were something of an anti-climax. That A Chorus Line proved one of the greatest popular successes of all time, and was accorded the title of "genius work" by critics, meant no other show he composed could quite measure up. Jean Seberg, a musical about the life of the actress, failed in London and never came to New York. The Broadway runs of Smile (1986) and The Goodbye Girl (1993) were both underwhelming. Sweet Smell of Success (2002), based on the classic 1950s film about Broadway's seamy underbelly, ran only two months.

His many film scores included "Ordinary People," "Sophie's Choice," "Three Men and a Baby," "Ice Castles," "Take the Money and Run" and "The Informant!" He co-wrote the song "Nobody Does It Better" for the movie "The Spy Who Loved Me."

In recent years, he composed some classical works, and frequently conducted major symphony orchestras.

PHOTO ARCHIVE: Remembering the Stage Work of Marvin Hamlisch