I think it depends on the concert but it is nice to look around and sit if most people are sitting. If a lot of people are up and dancing then I would feel free to stand. I like the idea of offering to switch seats with those behind you if they request you to sit.
This reminds me of a recent concert by Smokey Robinson in our local symphony hall (he is still great). Theater style seating and almost everyone was sitting. The guy next to me was so overcome that several times he got to his feet and needed to 'direct' the music. He apologized to everyone around but was so in love with the music that he couldn't help himself. No one minded, we loved seeing how excited he was. After all it was Smokey Robinson!
This reminds me of a recent concert by Smokey Robinson in our local symphony hall (he is still great). Theater style seating and almost everyone was sitting. The guy next to me was so overcome that several times he got to his feet and needed to 'direct' the music. He apologized to everyone around but was so in love with the music that he couldn't help himself. No one minded, we loved seeing how excited he was. After all it was Smokey Robinson!