It's be pretty lame and I probably would have never left Guitar Hero. I would have seen it as a stale and vapid experience honestly.If there were no background visuals at all, would you still play Rock Band?
I'd have thought it was something you'd do in a preschool class, playing color coded instruments to onscreen cues, solely for the sake of playing color coded instruments to onscreen cues. Like musical simon. I'd be fully expecting a lab tech to give me a treat every 10 minutes and adjust the electrodes on my forehead while I'm being observed on the other side of a two way glass by scientists.
I'd have laughed at anybody that wanted me to sit down and play it. "No listen! You hear that?! You press the button and Celebrity Skin comes out the TV!" To which I'd respond, "that's nice, can we take the musical tetris out of the system and play a game now?"
The band aspect is at least 60% of the game for me as i can't think of another reason I'd be playing plastic instruments other than playing a game where I'm in a band and in order to do it I have to play plastic instruments. Having a band visually on screen, not sucking, is a pretty big component of that aspect. I mean I used to play text based adventures back in the day, but after playing stuff like Fallout or Oblivion I'm in no rush to go back to the stone ages of videogaming. I need a bit more stimulation these days.
Facetiousness aside, the chart based play is fine for what it is, a play mechanic that lets you pantomime playing music, but that in and of itself has limited appeal, for me anyway. I need those added elements of creating a band and seeing the creations perform the song I'm playing live, they're the characters in game. Only thing is I have the benefit of instead rather than picking what someone else made to go onstage, the game lets me put my own motley crew up there a nice extra in the engagement and stimulation column. And seeing them onscreen is the payoff to that creative outlet.
Just my .02.