There's a great excerpt up over at Gamasutra from Iain Simons' book "Inside Game Design", which focuses (the excerpt, not the whole book) on Harmonix and in particular the history of the Guitar Hero franchise. All of it's interesting stuff, but none more so than this, which should please embittered Guitar Freaks fans upset the Guitar Hero games have stolen their thunder:
[Red Octane]was interested in making a guitar game as they'd seen Guitar Freaks, which Konami had done. So they came to Harmonix with the request, "will you make us a great guitar game for our new piece of guitar hardware?"
They could. They did. The rest is history, proving once and for all that all Guitar Freaks needed to succeed in the West was to make death incarnate a playable character and include a more sensible, appropriate tracklist.
Inside Game Design: Harmonix Music Systems [Gamasutra]