Pentatonix sounds more like the name of a DJ production team than a vocal quintet, but this Arlington, Texas-bred crew isn’t your typical troupe of harmony singers. With their intricate a cappella arrangements and breathtaking beatboxing techniques, Pentatonix form the missing link between doo-wop and EDM. This group was quite literally an overnight sensation: Originally a trio formed in high school by mezzo-soprano Kirstie Maldonado, tenor Mitch Grassi and baritone singer Scott Hoying, Pentatonix added bass vocalist Avi Kaplan and beatboxer Kevin Olusola just the day before they were set to audition for NBC’s reality-show competition The Sing-Off in 2011. After an 11-week run that saw them vocally revamp songs by Marvin Gaye and Kesha with equal aplomb, Pentatonix emerged victorious with a $200,000 cash prize and a record contract. But the group’s astonishing vocal interplay made them natural viral-video fodder, as they received as much attention for their inventive clips—such as an a cappella medley of Daft Punk cuts that could pass for a genuine club mix—as for their own official, covers-laden releases. Meanwhile, a handful of Christmas-themed records—featuring yuletide standards mixed in with wintry tunes by the likes of Fleet Foxes and Leonard Cohen—have made them as ubiquitous on holiday-season shopping-mall playlists as Mariah Carey and Mannheim Steamroller. But Pentatonix want you to know that there’s more to them than just pretty voices and excellent taste: Their self-titled 2015 album came loaded with originals—like the slinky neo-soul jam “Can’t Sleep Love” and anthemic stomper “Sing”—that proved they’ve got the songwriting chops to match their vocal ones.