I'm definitely not really qualified to give any "analyzed" feed back, but I will just give you some of what I see.
I like the bokeh of the background blended with the detail of the singer. It makes the singer really pop out giving it a nice 3-D look. The lighting on the subject also brings out the clear 3-D look. I'm not one to go to concerts, but for me I would have cropped the top and right side a little bit, keeping the same aspect ratio.
Remember, I am one who is very unqualified to give any good feedback. Ha!