So, I have this problem with hitting notes sometimes. For instance, I'll be playing along in a song and everything is going great, and all of a sudden I just miss/chip/biff a note. My instructor says it's usually because I lose focus and I'm just not thinking. But sometimes even when I am completely focused this happens. And I've heard/seen it happen to other people too. So does anyone else have this problem where they are going along and just miss a note or two out of the blue. And how do you fix that; just play a whole bunch of articulation and tonguing exercises perfectly all day? Any input is appreciated.