Katy first premiered the lead single off the release of her sophomore album 'Teenage Dream: The Complete Confection' at the Grammys, and since then 'Part of Me' has been a huge hit.  It's currently the #1 song on iTunes and has been for most of the week.  I think the reason for this is that we are seeing a very mature and raw version of Katy, rather than the cutesy 'California Gurls' version we are used to.  The song is basically about her break-up with Russell Brand and how he's never going to take away from her who she is.  It wasn't my favorite song upon first listen, but now I am loving it.  The emotion is just so powerful, strong and raw.  Katy's really ruling the world of pop music at the moment, and it'll be great to hear some new music from her soon.