Speaking from the point of view of an audience member, I would say that a good performance contains a number of common elements. To me, first and foremost, is that the performer be pleased and happy to be there- I'll forgive a lot when I know that. Then, good energy. Sighing or whining (whingeing) is a turn off. Don't complain about the boss or the venue or the audience or a band member. Then, a good mix of tunes and songs. Two thirds, say, can be original but present a number of them with which we, the audience, are familiar, if only to be able to gauge the P's skill or to complain of or compliment his/her version.

And never lose sight of where you are! A performer who compliments Anchorage audiences when s/he is in Juneau, say, does not make a good impression.