Could it be that he's stepping forward with his left foot while also swinging his left hand forward while looking to his right? (Whenever I want to look extra awkward, I swing my legs and arms in unison like that.) It's a pretty unnatural part of his stance to catch. I think this contributed to the centred crop, because you couldn't leave more space in the direction he's looking while he's travelling in the other direction.
Per your request for comment...I think it's a good capture. Lighting is excellent. I like the way he stands out.
Perhaps it is missing the impact of an interesting subject though...we don't know who that is...though it looks a bit like Kevin Bacon. And he's just centered standing mostly straight singing. That might work better with a recognizable singer. Even still, a close up shot showing emotion, or 'putting it all in' with corresponding light, would do much better in my opinion.
Nice pose and capture. I do take a flexible approach about the theme and in general I will rate a suggestive or impressive photo high, even if it doesnt't quite fit the theme. However, in this case I really feel like saying 'this is not a candid' :) Perhaps, aside of a direct portrait, a picture of a performer in action is just the anthytesis of a candid. I say this not as a criticism but to point out that there are is always a public side and an inner side to a performer on stage, and I have seen real candids taken at performances. An angry or worried glance because one of the other performers is out of time or because of some technical problem, a spontaneous smile between musicians which is obviosiously not intended for the audience. Backstage and end of concert moments. Perhaps, even at that specific event there were a few moments showing more of what the artist is and less of what he wants to show to the audience.