MASSAPEQUA - Marvin Hamlisch, the legendary composer behind dozens of classic film scores, passed away in Los Angeles yesterday following a brief illness. He was 68. Hamlisch was born in New York City, but spent many years of his life living in Massapequa and on the East End. Friends say it was on Long Island that he composed many of his best-known hits, including 'Chorus Line.' He wrote dozens of Broadway tunes and film scores, including ones for 'The Sting,' 'The Informant,' and Barbara Streisand's 'The Way We Were.' Hamlisch was one of just two people in the world to have won an Oscar, a Grammy, an Emmy, a Tony and a Pulitzer Prize.