Just to follow this up, here's a picture from the evening ( a few others are here: http://www.flickr.com …/97587508@N05/11040480553)
This was shot on my 6d, ISO 12800, 24-70 at 24mm, 1/100, f2.8
Like I mentioned before, especially during this band, the light level was extremely low since they only really had on the purple and red lights.
I wish I could've shot with a faster shutter speed, but I just couldn't do it without pushing the ISO to its usable limit.
Should I invest in a faster lens? Something like a 1.4 for venues like this? I'll look into using a flash at this venue.
Most of the pictures turned out either very grainy (from the high ISO) or with some blur. I'm hoping to make some improvements for next time.