Little different perspective.
When I listen to a record, tape or CD, I listen intently for every note and word, every nuance of the music. When I listen to a live performance, I am less concerned about the sounds, but very aware of the visual aspects of the performer. Does s/he act bored? appear to actually like performing? appear to like the song? give some measure of interpretation to the music by actions, expressions?? and so on. So I interpret the premature clap (how do you like that one, spaw??) as the audience saying, "Thanks for doing that one - you have no idea how many times I've sat spellbound listening to it." And it does not bother me at all.
But that's me.