Tough negotiations between the music biz and MTV could leave "Rock Band" without new downloadable tracks from one of the big four labels.

Billboard is reporting that MTV and Warner Music have been unable to reach agreement on a single deal since WMG chairman Edgar Bronfman decided last summer that his company deserves bigger royalty rates for music video games. The two sides have traded offers and haven't reached a compromise. For now, reportedly, there's content coming through the pipeline, but it'll be all out by early summer.

That could be a major blow to "Rock Band," which has prided itself on the wide array of tracks available to download, much more than for "Guitar Hero."

Given the tough business deals that Activision negotiates, you would think it would be in the tougher position with Warner. But it's apparently doing fine with Warner, as evidenced by the upcoming "Guitar Hero: Metallica" (a Warner Music act)

Of course, as I reported a few weeks ago, MTV is already losing money on the "Rock Band" hardware. If giving into WMG's demands (thereby probably triggering higher royalties to the other labels) would mean losing money on the DLC as well, I can see why it's playing tough. Some part of that franchise has to actually make a profit.