If you are going to a concert, one would assume you are paying money to see whoever is on and listen to them. Certainly it's not to listen to some gobby inconsiderate twat who seems to think that everybody is there to listen to them.
Most organisers try to ensure that the audience get to listen to the performer(s) and most of the audience are very respectful to whom they have come to see.
The intervals are for socialising if that's all you go for.
The Pub gigs are there for people who want to get pissed and talk through the complete gig (or that seems to be the trend these days).

Folk Clubs don't tolerate people talking whilst somebody is singing or playing a tune.

Best I have ever heard from the person (female)onstage is "If your (private part) is as big as your gob, you can have me tonight"