After their career started with an ironic hit, the Chainsmokers solidified themselves as dance hitmakers in 2016 with the eruptive hit "Don’t Let Me Down." It's a single that belonged as much on a festival set list as it did in the darkest electro-trap club floors, and it earned the Chainsmokers their first GRAMMY win for Best Dance Recording in 2017. It begs the question: How did they pull that off?