We’ve been playing quite a lot of Rock Band since we got it. While I’ve played a lot of Guitar Hero and as such am no newb to the ins and outs of rhythm-based games, I’ve never been able to play any harder than Easy.
Until now! I’ve finally graduated to Medium! I am so pleased with myself. I might even be so bold as to try bass on Hard, although that’s pretty damn ambitious. I’m finding Medium on guitar AND bass challenging enough for one reason only:

Yeah. My hands are not built for rawk. Reaching blue is difficult; orange would be damn near impossible. Still, I have a dream. Maybe someday!
Maybe you need a pinky extender. Like maybe those eraser heads you put on pencils?
Oooh that would be awkward! And yes, you definitely need to come over some time and be our drummer! I can’t get past easy on drums, but I’m rocking the bass!
move the whole hand :) is the only way to manage the yellow/red and then the mighty orange combos.