After the world-conquering chart success of its 2016 collab single with Halsey, “Closer,” and its 2017 full-length debut, Memories…Do Not Open, The Chainsmokers continued growing in 2018 with Sick Boy. On its sophomore record, the EDM duo pushes their dynamic sound into more shadowy sonic territory, with moody arrangements and darker, more introspective subject matter that reminds listeners it’s often lonely at the top. But more than just fleshing out the emotional world of The Chainsmokers, Sick Boy introduces new and varied sounds to its body of work. Recorded over a fairly lengthy span from mid-2017 to 2018, the record was released as singles each month throughout most of 2018. Opener “This Feeling,” with its punchy acoustic guitar riff and vocals from Kelsea Ballerini, adds some country to its bag of tricks. The dramatic piano lines of “Somebody” as well as the title track explore the alienation of modern living as the duo laments a feeling of disconnection. More overt nods to emo show up on “Everybody Hates Me,” a heavily pumping track on which the pair confesses, “I’m a product of the internet.” Late in the album, “Siren” (with Aazar) and the ballistic “Save Yourself” (with NGHTMRE) both go incredibly hard, employing mind-melting dubstep drops after cryptic lyrics about self-medicating and a breakup. Of course, this is still at its heart music to dance to. The funk and disco-tinged “Side Effects,” featuring vocalist Emily Warren, brings a taste of the ‘70s to The Chainsmokers’ vibe while providing some uplifting respite from the melancholia. The slow roll-out of Sick Boy proved so enjoyable to the duo that it employed it again with its 2019 follow-up, the star-studded World War Joy.