Cool! Well if you can set the ISO speed, set it for 800 or 1000, if it's too "grainy" take it down some. I think you should be able to set your aperature too, if so the smallest number you can get is the best (most wide open so more light comes in).
Try and not use the flash, past the fact it probably disrupts the band a little, I think shots with the flash look unnatural.
Example, two different photographers from same night, on my site.
With flash
Without flash