Best remembered for his jovial theme song, "Derwin's Melody", Hal Derwin (or Derwyn), had his greatest success on the West Coast's big band scene of the1940s. As leader of the Hal Derwin Orchestra, which he formed with former Jan Garber and Glen Gray saxophonist Freddy Large, he was signed by Capitol and had a six year residency at the Biltmore Bowl in Los Angeles that was broadcast nightly over NBC Radio.
Remaining active as a vocalist and, occasional guitarist, until the early-1950s, Derwin was featured on such hits as Artie Shaw's "That's For Me" and "Take Me back", which he recorded as a duet with Martha Tilton.
Following his retirement as a musician, Derwin worked as an A&R man for Capitol. He claims to have supplied "dubbed-in" vocals for many films featuring vocally impaired performers.