I've never 5* Saturday Night's Alright for Fighting on legacy Keys... I came so close yesterday though, and I missed a ton of notes.
However, on Easy Pro Guitar (shush I'm a noob :3) sometimes it's like... miss 2 notes and get 4 stars. Or or some Expert Pro Keys songs... miss 3 notes and get 4 stars.
The scoring seems out of whack here, and it's frustrating. Musicians make mistakes all the time in concerts - they're human. You don't hold it against them. Why should the game penalise me for missing hardly any notes?