I hate to bear bad news, but you are probably going to need a lens with a wide aperture to get decent shots at a dark show like that. The 50mm versions are inexpensive and fairly easy to find, but might not be easy to find in three days. A 50mm might not be enough focal length depending on where your seats are. Also, the Nikon version would be MF only because the D40, D40x, and D60 do not have a focus motor in the body.
Probably do what you want to hear, but IMO you should hold off on the camera until you can research more to be sure you get the right camera for you. It took me over a month to decide. I cannot imagine three days! Remember that it is more than a camera, it is a system. If you buy into a system before knowing what that means, you might regret it later.
Kevin