Guitar Hero World Tour

Start up a Band with at least four players and set everyone to Hard difficulty. Play any song and make sure no one in the band misses a note. You can strum extra and stop your note streaks, but you cannot miss any notes.

-Vocals counts total notes just like any other instrument, not just phrases. So, it is possible to have a 4x multiplier, but have less than 100% notes hit.

Some easier songs to choose from are:
No Sleep Till Brooklyn (harder on guitar)
What I've Done (harder on vocals/medium on drums)