Adele may be dominating the charts with her top-selling album 21, but Katy Perry is shaking things up with her new single, "Part Of Me." Following her performance of the song as part of a medley during the Grammys, the track debuted on the Billboard Hot 100 at the top spot. The last time a single debuted at No. 1 was with Lady Gaga's "Born This Way," a song that also got a boost thanks to exposure during the Grammys.

[via Billboard]