I don't tend to notice it that much and I might clap softly if I like a song...if a performer announces a song first that is a good time to get the pre-applause out of the way, too...

People clapping and screaming before a song is finished seems just rude to me, though. Worst experience ever was a Tori Amos concert in a relatively small theatre. Crazed women in the audience were screaming (I mean screaming) while Ms. Amos was singing, presumably because she sings autobiographical songs about rape and therefore she is everyone's personal guru of pain. Tori also does very soft intricate vocal interludes when she eases off the piano and peopel would scream during those too, when clearly the point of being softer was to get people to listen! I love her music and understand why women think she speaks directly to them, and why audiences thin kshe is an amazing performer because she is, but screaming during a song is not the way to show your thanks or admiration.

peg