Erato - Til The World Ends

After their cover of Robyn's Call Your Girlfriend featuring that beat, Erato have become a Swedish sensation. They favour tight harmonies and you won't find any Mariah-style runs in their Britney cover, but it's a demonstration of the beautiful sounds you can make with a few voices and a glockenspiel.

If you like this, watch their performance on the Swedish grammy's where they sing the nominees for Best Song. Granted, you'll know about two songs, but by the reactions of the nominees, Erato are doing something right.