Emily Warren plays well with others. The songwriter and vocalist has helped write many of pop's biggest hits, from The Chainsmokers' “This Feeling” to Rita Ora's “Only Want You,” but also has excelled outside the framework of pop. Her supreme balladry and nuanced storytelling fit acoustic and country troubadours like Jason Mraz and Brett Young as well as dance music superstars like Tiësto and Clean Bandit. But Warren can bring salty heat, too; tap Dua Lipa's “New Rules” and Sigrid's “High Five” for two of her best chin-checks.