Sheku Kanneh-Mason’s appearance last year as a castaway on BBC Radio 4’s Desert Island Discs was meant to be a celebration of the now 26-year-old cellist’s journey from winner of the 2016 BBC Young Musician of the Year to leading soloist on the international circuit. That is until the host, Lauren Laverne, asked him whether he thought Rule, Britannia! ought to be dropped from the Last Night of the Proms. When he answered yes, he thought it should, the backlash on social media was as vile as it was unprecedented with people calling for him to be “tagged, flogged and deported” and demanding he “go back home” and “keep his mouth shut”.

Sheku Kanneh-Mason. Photo © Mahaneela

“It was shocking how extreme it was,” he tells me, chatting over Zoom from the flat in Peckham, London he shares with his brother, violinist Braimah, and a guitarist friend. “I’m not unaware of those views, but the scale of the response, I felt, was disproportionate to comments I made that were personal, calm and measured.”

It’s something Kanneh-Mason addresses in his new book The Power of Music: How Music Can Connect Us All, an engaging and...