Every show at the Toyota Center is different. There are no set standards per that venue. That's part of concert shooting. Sit in the pit and anticipate what the opening note will bring you while the sweat begins to flow down your forehead.
I've shot shows that some songs were performed in almost total darkness. While others were lit up so great that the anticipated camera settings were immediately corrected.
If I know for sure that I am not shooting from the soundboard, I leave the 400mm f/2.8 at home. I've been able to get some nice images with standard zooms. I usually take three bodies with me and mounted to them are the 16-36 f/2.8, 28-70 f/2.8, and 70-200 f/2.8. Some times I shoot primes including the 50 f/1.4, 135 f/2.0 and the 200 f/1.8. I've recently purchased a 35 f/1.4 for concerts but haven’t shot a show since the purchase.
I usually can get by with 800 ISO and I normally use spot metering to change settings on the fly.
Some samples can be seen here as for different lighting conditions.
http://www.zeppzone.com/entertainment
What show are you shooting?