One Last Song Sam Smith Download 'One Last Song' on iTunes
Katy Perry performed a special version of 'Firework' with children's choir PS 22.
Katy performed the track as part of Oprah Winfrey's Ultimate After Oscar Party on Monday (February 28th).
She took a break from her European tour to fly into Los Angeles' Kodak Theatre for the performance.
'Today was such a beautiful day,' she Tweeted 'PS 22 & Oprah made ME feel like a firework...reforcused me & reminded me of my purpose. Thank you.'
See footage from the performance below