Katy Perry's Most Important Song

Katy Perry's "Teenage Dream" album spawned five number one singles, but one of them is more special to the star than the rest.  During her interview at Thursday's ASCAP expo, Katy said "Firework" was "the most important song" she's ever written.  She's taken her show to some of the biggest venues in the world and even sang for the President of the United States, but she said that the "most important performance" of her career so far was when she got to sing "Firework" with a young autistic girl at a fundraiser event last October. 

The singer also spoke about how her "Teenage Dream" follow-up is coming along.  Perry is back with her all-star production team including Max Martin and Dr. Luke to try and recreate the magic.  She said it's been her strategy to not write or record new songs while touring, and so far she's only started throwing around ideas with collaborators who continue to push and bring the best out of her.