There's a pub in Hamburg where - because he loves the music more than his profits - the landlord refuses to serve during sets and firmly stops anyone who talks too much, if the punters don't do it before him. But that's special.

I can think of several occasions where I got annoyed with people talking through a concert (not in a pub). I've been known to tell them I'd paid to hear the artist, not them, and would they mind shutting up? Usually helps, though it gets me black looks.

Mudcat's own Dita has written a song about it: A Man You Meet Every Day. Heard it from Iain MacKintosh, who was very good at getting people to quieten down by singing very quietly.