Better known as a songwriter than a performer in her own right, New York-born Emily Warren wrote songs for a whole host of high-profile pop acts, including Jessie J, 5 Seconds of Summer, Tiësto, and many more. Hailing from a musical family -- during her childhood her father frequently played guitar and sang to her and her brothers -- it was her childhood piano teacher who introduced her to the concept of writing her own songs. Growing up on the Upper West Side of Manhattan, she attended Trinity, a prestigious preparatory school, from kindergarten to high school. Displaying an affinity for music from an early age, she would form her own band, Emily Warren & the Betters, which featured future MisterWives members Etienne Bowler and Marc Campbell. "Not at All," one of the singles from The Betters EP, found its way onto the short-lived MTV series Skins. As for Warren, she went on to attend the NYU Tisch School/Clive Davis Institute in 2011, and signed a songwriting contract with Dr. Luke's Prescription Songs label in 2013.
After a move to Los Angeles, Warren co-wrote the song "Masterpiece," the third single on Jessie J's album Sweet Talker. This paved the way for her to collaborate with her longtime friend Scott Harris to co-write four songs from Handwritten, the platinum-certified album by Shawn Mendes. Released in 2015, the Chainsmokers' Bouquet EP featured the hugely successful single "Until You Were Gone," co-written by Warren and also featuring her vocals, a contribution that was widely praised. Warren and Harris would team up again shortly thereafter, this time resulting in another Chainsmokers single, the Grammy-winning, Daya-featuring "Don't Let Me Down," which went platinum and reached the Top Five on the Billboard Hot 100. "Capsize," her 2016 collaboration with Frenship, became a streaming hit that surpassed 300 million plays by 2017. That same year, Warren issued her own tracks, "Hurt by You" and "Something to Hold on To."