There are performers who, whether from lack of respect for the music or the audience or from some kind of idea that it doesn't matter, just kind of mail it in.

In our monthly pay-at-the-door concerts series sometimes it has been evident that the performer had done virtually no preparation. One actually informed us at the outset that he was not going to do any 'A' material, another (in her 40s) performed so kittenishly that we sat aghast- and she is a seasoned performer!, another, just last night, after telling us that he and his daughter had not practiced said that he had no idea what they were going to perform, and proved it. Which was a pity because his daughter has a beautiful and strong voice, and he himself used to be a professional, touring musician.

I'm not worried about it- there are plenty of performers who give us their all- but I do wonder about the phenomenon.