This is from Comedy Central's "Night of Too Many Stars" benefiting autism programs.

Jodi DiPiazza is a young girl living with autism who had the honor of sharing the stage with superstar Katy Perry. The two performed a rendition of "Firework" that brought down the house. Perry later tweeted, "I will never forget last night. It was the most important moment thus far of what I do."

Get a hanky ready. Seriously.