In a rare interview, the queen of pop talks to Matt Rudd about becoming a mum at 50, growing up the youngest Jackson and how music is her therapy.

On Saturday evening, Janet Jackson will take to the Pyramid Stage. It's too soon to say whether the 200,000 festivalgoers will be sunburnt or mud-caked — probably both — but she and her dance troupe will be resplendent in boas, sequins, catsuits and leather couture. "I've never been to Glastonbury," she says. "Is it really always muddy? I'm excited. Hopefully they'll like us."

It's certainly an imaginative booking. Janet Jackson wasn't