Many people tend to use flash to shoot concerts or events. While this is an easy choice, there are two main problems: first of all, it is not always allowed to use flash to avoid disturbing the performers, and secondly, using flash allows to expose properly, but "kills" the light. If there are light effects or nice colors in the scene, they will be "removed" by the flash, giving a somehow natural color to the whole scene (with the exception of part of the background is you use a slow shutter speed and synch).
So, basically, even if I am an enthusiastic
user of flashes under
other circumstances, during night events, I try never to use flash. The
problem
is then, that the performers are usually human beings and hence are moving.
This means that to be able to freeze their movements you'll need VERY
fast (and
expensive) glass on your camera. To be concrete, even high end
professional f2.8 lenses might be too slow for that kind of application. My
recommendation is to use f1.8 primes if you are on a budget and f1.4 lenses if you have some
more money. Not so many AF lenses are available in that category: Nikkor 50
1.8, 50 1.4, 35 2, 85 1.8, 85 1.4 (very expensive) and 105 f2 (also expensive)
are the only available choices (or optionally the Sigma 30 1.4).
If you can use MF lenses (you'll need a pro or semi-pro body to be able
to use them, like any D2xx), there are more affordable choices (used of course,
those lenses are not being made anymore).
Nikkor 35 2 or 35 1.4, 50 1.4 or 1.2, 85 1.4, 105 1.8 all AIS
(excellent
professional glass)
My personal favorites: 35 1.4 AIS, 85 1.4 AIS, 50 1.8 AF and 105 1.8 AIS
If you want to shoot overviews or if movement is not an issue, the recent 18-200VR is fantastic (flexibility and range, while having the stabilization to allow you to shoot at ridiculous shutter speeds)
Even if you shoot at say f2, depending on the conditions you might even need ISO1600 to get a decent shutter speed, but the result is worth the effort.
A few examples (85 1.8 and 105 1.8)
This is an ISO1600 shot (D200)
