The Hero series was all over the place at one point. Spin offs and iterations were everywhere, and over saturation effectively killed the genre.
However, a rather radical project that never saw the light of day has just surfaced. The good people at Unseen64 have unearthed this gem, and MMO set in the Hero IP. Hero World didn't actually have anything to do with playing guitars directly, but rather functioned as a live hub for all the games to be tied to each other. It revolved around club management, and even had a tie in Facebook game to go with it too.
Take a look at the pretty out there concept for the game here.
I don't really think this would have had a massive chance at succeeding all told, but it's always interesting to hear about cancelled projects.