Songwriter/musician/producer Andrew Watt's keen sense of melody and sharp lyrical acumen translate to almost any style of pop. He kicked up the heat of Camila Cabello's Latin-tinged “Havana”; he helped give Sleeping With Sirens' sweeping ballad “Need to Know” its wistful heart; and he depicted post-breakup confusion vividly on Avicii's Rita Ora collab “Lonely Together.”