not too sure where you are seating.. but you're probably some distance away from him.. even with steadyshot i dun think you will be able to get clear pictures.. besides if you are just "seated" there.. probably wouldn't have many interesting view / perspectives..
and as you said.. flash is a no no.. besides you are so far away from him.. dun think any flash will be helpful.. other than to make the "heads" in front of you white.. =)
can try upping your iso.. that's the least you can do..
why not sit back and enjoy the concert.. (singing along maybe?!) =)