Pentatonix

The earliest recipe for apple pie is from fourteenth-century England, so maybe a better phrase would be 'as American as Pentatonix'. They've got it all: the Texas upbringing, the high school beginnings, the 'Glee'-inspired acapella tunes, the rise to fame on an NBC talent show and on YouTube and (most importantly) five perfect sets of gleaming white teeth. So yes, they're almost sweet enough to rot your own gnashers – but they're a talented bunch, beatboxing and harmonising all over the shop and interpreting everyone from Survivor to Kanye.