Today's announcement from Harmonix and MTV Games is one for the metal heads. They are making the music of eight of the artists on the RockStar Energy Drink Mayhem Festival available for download. Marilyn Manson, Slayer, Cannibal Corpse, Behemoth, Black Dahlia Murder, Job for a Cowboy, God Forbid, and White Chapel are each contributing one song to the Rock Band Music Store next week.

The Mayhem Pack will be available for $13.49 or 1,080 Microsoft Points.

* Behemoth - Conquer All
* Black Dahlia Murder - What a Horrible Night to Have a Curse
* Cannibal Corpse - Hammer Smashed Face
* God Forbid - Empire of the Gun
* Job for a Cowboy - Embedded
* Marilyn Manson - Disposable Teens
* Slayer - Black Magic
* Whitechapel - This Is Exile


Additionally, a Green Day pack with three exclusive tracks is on the way. It will be available for $5.49 or 440 Microsoft Points.

Both packs will be released on July 7th for Xbox 360 and July 9th for PlayStation 3. As always, they will be compatible with Rock Band and Rock Band 2.