Kirk, Actually, ‘Pre-Produ
Videomaker – Learn video production and editing, camera reviews › Forums › Technique › Writing and Pre-Production › Pre-Production for shooting in a theater › Kirk, Actually, ‘Pre-Produ

Kirk,
Actually, ‘Pre-Production’ is the process of research/planning the acquisition of money, resources and personnel needed to produce a completed film or video.
You are already in the ‘Production’ stage and though the video Finity posted is great for a controlled setup, your issue on-stage during a live event sounds primarily like you just need to ‘close down’ on your exposure to get a better looking image of the dancers.
In the detailed user’s manual, there’s a description for the ‘Manual Settings Menu’ items you can pull up on your camera. You want to adjust the Brightness until you cut or raise the light level the camera sees to what works for you. There’s another setting that Adjusts the way your camera sees the light coming into the camera called ‘Metering’ that you can use as a back up. However, the Brightness setting should get you where you need to be.
If possible, prior to your next session go shoot one of the dress rehearsals and get all the bugs worked out. If you can’t, show up to the theater early as possible to get set up and test out your exposures with the Brightness setting by getting the stage techs to shut down the house lights and turn on the stage lights. Now, remember that white, blue, red, green and yellow will require adjustments to the brightness.