For some reason this sticks in my mind, though I thought it was earlier than '84.
The plot revolves around a young band and a supposed producer but con-man who is rumbled by his lack of knowledge of the titular song.
The episode stays vaguely in my mind after all this time- quite a feat given that the mid 80s was the last time it was ever shown. So It has to be a commendation of sorts.
Dramarama was a pretty unique 'Play For Today' style anthology for children and teens and wasn't afraid to tackle mature or unsettling plots.
It's a uniquely British style Children's TV show which sadly is long now extinct, and has been culturally displaced by the 'Nickleodeon' Culture.
Pity.