Dan Smith is a busy man. The Bastille frontman is juggling the imminent release of his band’s third album (which he also co-produced), with running a label and a recording studio, in addition to penning songs for other artists. His Marshmello collaboration Happier is now a certified worldwide smash, charting at No.2 on both sides of the Atlantic. Oh, and he ran this year’s London Marathon...

“It’s about trying to do everything at the same time and create as much ...