Ed Sheeran famously keeps one eye on the numbers. A decade ago, he established his trademark, a pop take on the sensitive singer-songwriter trope with a healthy relationship to rap and R&B that has allowed him to flit across genres, imposing his indelible style on everything from Afrobeats to Eminem and Bring Me the Horizon collaborations. It’s the smartest thing a pop star could do at the dawn of the streaming age, where success is tied to your ability to feature on as many genre-themed playlists as possible – a strategy borne out by Sheeran’s 150m record sales – but also proof of fairly absurd talent: if it was that easy, everyone would be doing it. Under the circumstances, it’s hard not to be impressed by how wholeheartedly Sheeran has thrown himself into his fifth album, Subtract, a noticeably different prospect to previous albums.