It's an excellent question, but I think it's the wrong one. When I started my masters degree program, I experienced writers block for the first and only time in my life. My very wise composition teacher at the time was Marty Sweidel. He said, "Kurt, this can often happen when you start your Masters degree. You are all blocked up because you are trying to write the great American Symphony. Just write stuff, and stop trying to be brilliant."
A much better question for people involved in creative activity is, "Is it honest?" That's a tough question to answer sometimes. It's especially hard to explain to someone outside your discipline. I find it incredibly difficult to explain to anyone why a G# in this spot feels like some sort of compromise. I imagine it is the same for other disciplines. That little spot of grey in the painting makes it less comprehensible but more "right" somehow. A little bit of Teutonic sentence structure, while obfuscating the main point - and at the same time clarifying it, works.
For me, if I am focussed on being honest, I cease to worry about whether what I am doing is derivative. It necessarily will be derivative in some spots because I am participating in a tradition. Originality grows out of honesty because we are unique. Let me say that again. People create unique things because people are unique things. It's only when we are pretending that we are not that we get into trouble. When you set out to be original, you already have your eye on someone else. That is the death knell of creativity.
