New York City bus riders got a rocking surprise Wednesday when Macklemore & Ryan Lewis climbed on board.

The duo quietly got onto a city bus and began performing their hit "Can't Hold Us" to a group of unsuspecting commuters. Initially the riders looked on as if it were the everyday mass transit performer, common in the Big Apple. But when Macklemore pulled his hoodie off, they realized it was, in fact, the musical stars.

For a unique Grammys promo, which is part of the "Music Unleashes Us" multiplatform ad campaign, the patrons quickly got on beat clapping, dancing and cheering on the surprise performance. Macklemore & Ryan Lewis are nominated as Best New Artist for the awards show airing Sun., Jan. 26 on CBS. And by the way they amped up the entire bus with just one verse of their hit single is proof as to why they've been pegged in that category.