It’s 40 years since Madonna began scandalising and delighting fans and critics around the world. But is she still misunderstood? With Mary Gabriel.

She’s an enduring global superstar, with 330m albums sold worldwide. And she has just begun the US leg of her first greatest hits tour, celebrating 40 years in the industry. It’s hard to think of anyone who is as overexposed as Madonna – but, says her biographer Mary Gabriel, fundamental misconceptions about her remain.