Katy Perry's 'Teenage Dream'

The hits just keep on coming. In advance of the singer's "Teenage Dream" album release, the star unveiled the artwork for her single, "E.T." The track is the next to be aired from Perry's LP. Other wildly successful songs off the album include "California Gurls," "Teenage Dream," and "Firework."

15 Films Defined by Songs of a Single Artist

 Christina Aguilera's new movie, 'Burlesque,' continues a long tradition, from 'Jailhouse Rock' to 'Purple Rain' to 'The Bodyguard,' of singers starring in films for which they also dominate the soundtrack. Which got us thinking about singers who have defined the sound and spirit of an entire film without ever appearing onscreen. Here are 15 of our favorite examples of singers whose voices alone are like an uncredited main character.

Best Songs of 2010

Once upon a time, we might have gauged the best "singles" of the year just ending, but popular music circa 2010 has shifted the conversation back to the fundamental – the song. The rules have changed with the proliferation of a la carte options for curious listeners: Conventional singles are multiplied by remixes, EP samplers, demos and alternate versions, giving MSN's contributors a vastly larger bucket of tunes to contemplate. Our top-ranked songs do include some well-known hits heard on radio or seen in videos, but our contributors' submissions tell a more tangled tale of fave musical moments.