To me what matters is having an original style. Elfman really does.
And John Williams - who was a while ago criticized by pseudo-intellectual morons for "stealing" when in reality all his own themes are his own very distinctive sound - absorbs the many influences he is acutely aware of, being a vastly knowledgeable musician and supremely talented conductor as well as a great composer. But they are all part of his own scores - unlike James Horner who deliberately, calculatingly and cynically stole completely and blatantly entire sections of music from classical works, including even the orchestration of such thefts. He was a shameless plagiarist, and an extremely mediocre composer who obviously needed to steal because he couldn't come up with anything of his own worth shit. If you'd like a demonstration of that - listen to Star Trek by Goldsmith - one of the all-time great masterpieces of film music - and then the godawful trite garbage Horner wrote for Star Trek 2. Endless augmented triad arpeggios that make one want to puke and a truly insipid, uninspired main theme. Then more stealing from anything he could get his grubby mitts on. A great film marred by a stupid score by a hack. BTW his major (and expected) plagiarism in that particular film is Prokofieff's FILM SCORE (!) to Alexander Nevsky. That is the Khan theme. Just check out both if you don 't believe it.
John Williams is poles apart from that sort of low-life plagiarist, and is within the same area as other great composers who can't help being deeply influenced by the wonderful music they are profoundly aware of. Williams loves the music he conducted regularly and yet his own is a new contribution that has his own signature style.
Uh-oh - this turned into a rant about film score plagiarism! How'd that happen?