Hi Verve
I've done a bit of band photography, not much but you can see some of it here
http://www.perceptive-photography.co.uk/photography-gallery/view/10There are a few techniques that I could recommend.
Second curtain flash sync would be the first. What camera and flash have you got? Basically you use a slow shutter speed to capture the motion and the flash to freeze a moment of sharp detail just before the shutter closes. This allows you to capture the movement at a gig but still retain sharp elements.
If your flash has a zoom function try zooming the flash right in so that you only illuminate the center of the frame. This works even better if you can use your flash off camera?? Do you have a flash sync lead or wireless trigger? Try under exposing by a stop or two, this tends to darken backgrounds which can be messy at gigs.
You mentioned not using a flash at all. In my opinion this would seriously limit your creativity. Your IS will work by reducing camera shake, it does nothing to the movement in a scene. Assuming you are shooting at F4 and maybe 3200ISO you are still going to struggle with shutter speeds.
Rather than reserving you wider angle lens for crowd shots maybe try and get close up to the action with it. You can get some quite dramatic results. Like looking down the neck of a guitar for example.
Metering can get confused with all the lighting going on at gigs, sometimes it better to set your camera in manual so you get consistant shutter speeds and exposures.
Just my 2 pence worth, as I say I haven't done much myself.