The 10D will save your but with its ISO settings! 
Don't use higher than ISO 1600,.. but 1600 looks remarkarbly good!
What sort of lens do you have? Obviously the larger the aperture the better for low light,...
Are you a point and shoot person,.. or are you comfortable with manual settings?
I ask as the first dark concert I did with the 10D and a fast lens I was still pretty much point and shoot only,.. however as the show progressed i finally settle don a manual aperture and shutter settings,.. this was the right choice as the photos I took manual were far superior to the auto ones I took at the beginning of the show.
Use "Partial" metering most of the time,.. it looks like ( ) on the lcd display... 
The way I settled on exposure settings is by metering (using partial) a model that ws dressed in medium tone colors,. Not bright white and not too dark,. (actaully I did this a few times) and read the shutter and aperture setting that the camera used in "P" mode,.. I then locked in this setting by swithching to manual and dialing them in,.. I confirmed that all was working,. and all the rest of the shots came out perfect.
The problem with this method is that this was a fashion show and the lighting did not change,.
at a concert it is very likely to never stay the same 
So I don't know how well manual settings will work for you....