Hayton's involvement with Bing Crosby continued and he was made musical director for the singer's film Going Hollywood (1933) which was a Metro-Goldwyn-Mayer production. This was to be the start of a major career for Hayton in Hollywood. He continued to work with Crosby on radio (Bing Crosby Entertains) and record for a while but in 1940 he became a musical director for Metro-Goldwyn-Mayer and guided it through its prime years as forerunner of the movie musical. Up until his retirement from the post in 1953, he racked up four Oscar nominations: for the Judy Garland musicals "The Harvey Girls" (1946) and "The Pirate" (1948). Hayton won the Academy Award for music for "On the Town" with Roger Edens in 1950. Lennie Hayton also arranged the music for "Singin' in the Rain" in 1952. Hayton notched up two more nominations—one in 1968 for the unsuccessful Julie Andrews musical "Star!" and his last the following year for the Barbra Streisand vehicle "Hello, Dolly!" co-composed with Lionel Newman, which brought him his second and final Oscar. In 1970, Hayton arranged Frank Sinatra's first attempt at the George Harrison composition "Something". However, Sinatra later began using a Nelson Riddle arrangement of the song in concert performances and, in 1979, he put the Riddle version on record. Hayton composed "Apple Blossoms" with Joe Venuti, Frankie Trumbauer, and Eddie Lang. His other compositions included "Flying Fingers", "The Stage is Set", "Mood Hollywood" with Jimmy Dorsey, and "Midnight Mood". Hayton also co-arranged the Hoagy Carmichael composition "Stardust" with Artie Shaw, for Shaw's recording of it in 1940, for Bluebird Records.