Souped up on California sun and psychedelics, Harry Styles’ Fine Line was a celebration of songwriting that showed a new side to the One Direction star. No one was closer to the record than co-writer Kid Harpoon (aka Tom Hull). Here, he tells the story of how they made a modern pop album like no other...

KID HARPOON: “Harry and I did some songs together on his last album. We got really close and when conversations started coming up ...