Quinn I have a friend who does concert photography here in the UK, he is not a professional and he does not sell his pictures, but he gets passes to take pictures from the front usually for the first couple of numbers. All he does is write and ask, the organisers seem to be quite happy to let him, you could try that approach it might work and it will be a lot cheaper than a f1.8 lens. :O)

Those who do not want to imitate anything, produce nothing. Salvador Dali