That'd be awesome. Its amazing how many people can't read standard notation or Tabulature but are awesome at Guitar Hero/Rockband. That'd be amazing. Think. You're playing games and you don't realise your learning, that'd be awesome.
I mean, a lot of people can already play stuff and understand Notation, but- if its part of the game it means people who don't know learn and people who do it doesn't make a difference. Its good idea.
I mean, If Mr.RockBand3 said "what would you do to incorperate this?" I'd proberly say make the harder the difficulty *Easier - Easy - Medium - Hard - MADNESS* The more like real music it gets. So- for singing you'd see the actaully notes for some(only some) so you'd have to try and sing by knowledge.
Thats just mah idea though.