Well there is a sort of grey area, which is more black for some, and more white for others, between talking a bit about what you're singing or playing - e.g. who wrote it and when and even perhaps why. I find this sort of stuff interesting, and absorb it like a sponge, even self-confessed anorak: whereas I know others who just go glassy-eyed, roll their eyes, and mutter, "get on with it", and couldn't care less about what the background is to whatever they are trying to sing or play. All in proportion, I'd say.