Wonderful to Be Young! (1961) on Netflix

Nicky and his friends find that their youth club is in danger of being flattened to make way for a new office block unless they can come up with £1500 to pay the new owner, the ruthless property tycoon Hamilton Black. To help raise the cash, Nicky records a song and his friends broadcast it via a pirate radio station, touting him as "The Mystery Singer" - the plan works and interest in their up and coming show is heightened by this new but unknown heart-throb. But Nicky has an even bigger secret and one that he cannot share, even with his girlfriend Toni... Hamilton Black is his father.