There's a new PC Guitar Hero clone in town, and this one is much more of an outright clone than the popular Frets on Fire. Going by the title Guitar Zero, the game pretty much blatantly rips off GH, menus and all. The song interface itself is only slightly different.
Same meters, same scoring section, same song listing down to the font and layout. As it stands the game only supports a guitar controller, so you'll need a PS2 to USB adapter to play it.