Although the music war seemed to have started once both Rock Band and Guitar Hero III: Legends of Rock had been launched on the market, it appears that was just the beginning. Yesterday, Harmonix Music System released a statement that accused Activision of blocking a patch that would allow Guitar Hero III guitar peripherals to work with Rock Band’s PlayStation 3 version.

Harmonix said that the patch was submitted to Sony and approved for release on December 4. But instead of releasing the patch, Sony informed Harmonix about Activision’s objection.

“As we have said in the past, Harmonix and MTV Games believe in an open standard philosophy of hardware and game compatibility. We think that there should be interoperability between music instrument controllers across all music games. This is clearly in the best interest of consumers, game developers and console manufacturers and will only help to grow the music game genre as well as inspire innovation and creativity,” Harmonix said in the beginning of its public statement.

At the moment Harmonix’s Rock Band is available only in bundle packages, which include one guitar controller, one drum controller and one microphone. If players wanted the entire four-player experience on Sony’s PlayStation 3 gaming console, they would currently have to buy an entire second bundle, as guitar controllers are not available separately. Thus, the patch Harmonix created would sound like any PS3 user’s dream Christmas gift.

Harmonix is the creator of the Guitar Hero franchise and developed Guitar Hero, Guitar Hero II and Guitar Hero Rocks the ‘80s before being acquired by MTV Games. While the Guitar Hero franchise was bought by Activision, Harmonix created Rock Band. And the music war started!