Out of interest, what were the camera and lens settings for these ? The top one particularly has a nice atmosphere to it. Not bad considering the conditions, + I'd make a bet that if they are NEFs you can extract a lot more from them.
I've tried a few stage events although with much more even lighting - nothing with quite your contrast range, and I've done OK with my 50/1.8. However it can be a bit long and a 35/2 would probably be a nice choice for wider coverage. That's why I'm interested in the FL and aperture etc you used.