Because the Mickey Mouse Club show was still being cast while the records were being made, few of the actual Mouseketeers appeared on the first recordings. One of them was Lonnie Burr, whose chance encounter with the recording session changed his young career. He met Jimmie Dodd, who was cutting Mickey Mouse Club Records. A kid dropped out at the last minute and Jimme asked Lonnie to fill it.
[Disney Mouse Tracks: the Story of Walt Disney Records by Tim Hollis & Greg Ehrbar]