Hi Will,
Your comments remind me a lot of when I first started taking photographs of bands back in the late 1980s. Having spent an evening photographing a band with a flash on my camera I was duly chastised by the lighting technician; he wanted to know why I was using on-camera flash when he had gone to the trouble of lighting the stage for the event. Soon after that I gave up on using flash and began making use of available-light photography.
Flash photography can be distracting both to the performer and the audience, but the light from a flash is also very flat and ugly. It might make it easier to take a photograph but it really does kill the ambience of an environment.
On the whole there is nothing wrong with the photo you have captured here. About the only adjustment I would make is to the white balance of the picture. The photograph does appear rather orange but if you had manually selected the tungsten white balance setting, or manually adjusted the colour temperature, you might have achieved a more appealing result. Alternatively, if you shoot in RAW it's a very easy matter to alter white balance in post.
Try experimenting with the white balance; it really does help if you can take some control over it rather than relying on the auto setting all the time.
Cheers, Anthony.
Image Doctor's edited version
