On the DVD commentary for Young Frankenstein (1974), Mel Brooks says that his two favorite scores from Morris are for that particular film and The Elephant Man (1980).
Starting with The Producers (1968), Morris was the "housecomposer" to every film directed by Mel Brooks until Life Stinks (1991). He also scored the Brooksfilms productions of The Elephant Man (1980), To Be or Not to Be (1983) and The Doctor and the Devils (1985).