The lines are getting more than a little bit blurred out there in the music game world. Developer Harmonix, remember, created Guitar Hero for Activision, before being headhunted to invent Rock Band for MTV and Electronic Arts.

Now, in Guitar Hero 4, the Activision game is adding drums and microphone support, blatantly copying Rock Band and making pretty much everyone in the world more than a little confused about why the two series seem to be converging and eating each other in public. Here’s the official GH4 trailer:

Slightly insane. Playing guitar riffs on the drums? Singing? Lenny bloody Kravitz? With Rock Band taking off…