It didn't take the British record companies long to notice they were missing out when the Americans invented the weenybopper singing star. The latest to join the race to manufacture a British little Jimmy Osmond is EMI, the world's biggest record company. Their product, 12-year-old Darren Burn, seems to have all the right ingredients: he's pretty, he can sing and his dad's an executive at EMI. John Pitman has followed the marketing of Master Burn, Ricky Wilde and the James Boys, and talked to their families.