It's not really singing, were not sure what it is, it's certainly tough to listen to. Yoko Ono has decided to cover Katy Perry's Fireworks but you probably wouldn't know that's what it was meant to be if we hadn't told you.
The good news is that this wasn't originally meant to be a Katy Perry cover. This is indeed Yoko performing in 'song' but a Youtube user has decided to put it together with the Fireworks soundtrack. There is another mash up option with Adele as well.
The Yoko Ono piece was originally created in June 2010 but has had further attention now that it is being touted about as a cover. The original 'screaming piece' was part of a serious exhibition called Voice Piece For Soprano & Wish Tree that was performed occasionally in conjunction with the exhibition Contemporary Art from the Collection.