I have check some reviews of your camcorder and everybody was pleased with the picture quality, BUT NOT WITH THE AUDIO QUALITY.
It seems that sony have save some money on the audio circuit. Is it possible to adjust the sound level (when you are recording) on the camcorder or is it controlled by the camcorder itself (AGC)?
If you want to record the sound from the masquerade you need to have the mic placed on the scene for having a good result.
And for this you need a good microphone tripod that are acoustic isolated from the floor, so you dont get the noise from people walking on the stage in your recordnings.
The best will be to get the sound from the mixerpult, but I think that the sound engineer wouldn't let you do that