First of all you should note that we're borderline happy as a community about identification questions at all. We have some users (and moderators) who are pretty against them, and a few that like them a lot. I'm on the fence, they don't add a lot but they do attract people to the site.
I think the simple answer is that we're not a Music site - so we don't allow 'identify this piece of music which just happens to be in a movie or TV show or music video' questions.
I don't think we'd consider an 'identify this movie from a score' to be off topic though. That's an identification question with a movie as the objective. It would be better if it were accompanied by other details, but personally I wouldn't close that.
Where should you go? Well music.se is for "Musical Practice & Performance" so not there. There is not currently a site for this on StackExchange. You can try launching one using Area51 - there are a number of Music related proposals needing support.