How do i get permission from the record companies to stream their music videos?

Hi there,

I am interested in developing a website that will stream popular music videos from the biggest artists and i just wanted to know how i go about getting legal permission to do this? I know i need a license from the PRS but i have also been told that i need to get permission from the record companies too and I just wanted to know if anyone knows anything about this? Will they charge me a lot of money for instance to stream these music videos from my website? Or is this permission usually granted free if they can see that your website will help them promote their music artists?

Anyway advice and help would be welcomed.