I shot freelance concert work for about seven years, although I wouldn't touch that scene with a ten foot pole now.
Have you shot concerts before? For concert work, you're going to want the WIDEST possible aperture. f/2.8 at least. Anything slower and you'll be looking at blurry images when you get in dark environments.
On my Nikon D70s body, I had great success using a Nikkor 50mm f/1.8 lens for wide shots. Just make sure you're set up waaay back from the stage for that, preferably with the camera stabilized with a tripod or (at the very least) a monopod. I highly recommend the 50mm prime lens as a staple in any photographer's bag.
This
SHOT is one of those from my 50mm lens, at my final time shooting at the Hard Rock Live in 2007.
I also used a Sigma 28-70mm f/2.8 EX DG for a lot of wide angle stage shots, it did a pretty good job /and/ it was versitile enough to get both wide and some closer images.
THIS is an image I caught with that lens at the Hard Rock Live in 2005 or 2006.
For my close-cropped, individual band member shots I typically used a Sigma 70-300mm F4-5.6 APO DG.
Like
THIS shot, also taken at the Hard Rock Live in 2005.
Most of these lenses, you can get for $100-$200 or so.. less if you buy them used or on eBay... the Sigma lenses may not be 'name brand,' but they're not bad quality. They've put up with some tough, tough conditions and survived!
Good luck! And if you need any further info on concert photography, send me a PM and I'd be happy to share some of the techniques I've learned over the years. =)