Pharrell Williams and the Eagles are among the artists leading a one billion dollar lawsuit against YouTube demanding the removal of their music videos.
Irving Azoff, founder of new legal group Global Music Rights (GMR), represents up to 40 artists including Pharrell, John Lennon, Chris Cornell and Smokey Robinson, and has claimed that YouTube does not have the performance rights to thousands of songs by his clients.
As a result lawyers are demanding the removal of around 20,000 videos from the streaming service.
Azoff was asked by the Hollywood Reporter why they are targeting YouTube in the £643 million lawsuit and not other subscription services such as Spotify.
He said: "Because they are the ones that have been least cooperative and the company our clients feel are the worst offenders. It's also their attitude."
YouTube owner Google - which is planning to launch its own subscription music service Music Key in the new year - has insisted it does have the performance rights due to prior deals.
But in a letter to YouTube, GMR lawyer Howard King wrote that the service has not provided details of prior agreements.
He wrote: "Without providing a shred of documentation, you blithely proffer that YouTube can ignore the Notices because it operates under blanket licenses from performing rights organisations other than Global. However, you refuse to provide the details of any such license agreements, presumably because no such agreements exist for YouTube's present uses of the Songs in any service, but certainly with respect to its recently added Music Key service."
But Google lawyer David Kramer responded that GMR must not only submit a statement under penalty of perjury that it is authorised to act on behalf of the owner, and not only identify the works at issue, but also identify URLs where infringing material resides. That would mean sending a takedown notice for each of the multiple videos using the 20,000 songs.