DeLyon performed on stage as pianist and vocal entertainer, and was musical director for several artists such as Sandler and Young. He worked on Al Kooper's first record. DeLyon recorded 45s, 78s and LPs using multi-tracking and his voice as instruments, long before Bobby McFerrin, as early as 1951. He recorded an album of Jewish humor in the 1950s in England, which led to a world tour and his classic LP Leo's Here.