The Patsy (1964)

"Jerry's a dumb-like-a-fox bellhop that some smart alecs manipulate into stardom..."

Eccentric bellhop Stanley Belt is recruited unexpectedly by the comedy team of a recently deceased entertainer. Stanley struggles to become a song-and-dance man as the team grooms him to become a star. But as the date of a high-stakes appearance on the Ed Sullivan Show grows near, they begin to fear that the only astonishing thing about Stanley is his utter lack of talent.