What are good lenses for high school concerts?

I have a Nikon D400, and a Nikon AF-S Nikkor 18-55 mm lens. IS this a good lens for a dance concert, or should i get a better one?

I have usually found that sort of focal length to be too short.
When I take photos of my high school daughter, I tend to use my Canon EF 70-200mm f/2.8L IS USM, and often enough even reach for the extender, too.