It's Only Rock and Roll
David Jason, Nicholas Lyndhurst & Buster Merryfield
This is episode #4 from Season 4 of the series.
Rodney forms a band with three mates. But when Del steps in telling the band that they would never make it big, he forces Rodney to drop out. The hilarious catch at the end is at the end of the episode the band without Rodney are on "Top of the Pops".