Like a decade or so ago I ended up coming to the realization that originality is so relative that it's really a pointless discussion. It's relative to the amount of knowledge you have of what already happened. On the other hand, the "spirit" of originality is a cool thing, which is to take the stance that as long as it's original to YOU, then it counts and it's worth looking into. Eventually as you get older and become knowledgeable, it's hard to perceive things as really original in the sense of "Nobody's done this before!" Rather, you end up putting a lot more value on what each person can bring from their own creativity.
Ultimately, I think that's the best way to describe my stance on it. I see everyone's musical input as original seeing as there's only one of each person with a unique perspective. Does it render the word kind of meaningless? Yes, but I did say that I thought it was a pointless discussion at the start didn't I?
Another thing of course is the fact that our brains work basically in the same manner, generally speaking, hence there is a very large degree of similarity in the way people tackle musical things and that of course cuts down on the "originality" business quite a whole lot. You end up only with cultural deviance or outliers if you're looking for something different enough to count as "original". It's sobering to realize that the hypothalamus(and friends) is responsible for a vast majority of musical structure (among other things) across basically all cultures, but stuff like that brings into perspective that a novel interpretation of "originality" is really a fickle thing.
Also:
I wrote that in 2009, basically as I was exhausted with philosophizing this very kind of thing. I figured, a performance held IN YOUR MIND, is going to be infinitely unique to each and every person. Kind of taking the idea of "originality" and running it right into the ground at full speed.