Scott Harris' years-long creative partnership with Shawn Mendes has gifted the Canadian troubadour with hits like the pleading “Treat You Better” and the anthemic “In My Blood.” Harris' versatility—he's worked with artists as varied as the bro-EDM duo The Chainsmokers and the brooding singer Alessia Cara—is matched by his instinctive approach to songwriting; the payoff is relatable lyrics that collide with massive choruses.