In flowering plant taxonomy there are lumpers and splitters. Take a species, a genus or a family and you'll have those botanists who will include and those who will exclude. I'm suspecting not dissimilar sentiments in threads like this one. Meanwhile, the
poor old music sits there in the middle, doing what music does best, being wonderful in different ways to different people. I think it was Vladimir Ashkenazy who said something like, this whole bloody music thing is a complete mystery to me...