From "Back to the Future":
Marty McFly (Michael J. Fox, Family Ties), who has gone back in time, fronts the band at a school dance where his parents eventually meet and fall in love. But if you think Fox did his own singing and guitar playing on a cover of Chuck Berry's immortal classic, "Johnny B. Goode", prepare to be disappointed.
Mark Campbell of Jack Mack & The Heart Attack was the actual vocalist on the following clip, while Tim May, a session musician, played the guitar solo mimed by Fox. Don't worry. Fox would finally do his own singing several months later in "Light of Day".