I am sorry to say that with you being 60 feet from the stage, this was an impossible photo situation. The flash on your camera went out to about 10-to-12 feet only. That is whyyours was probably a totally dark or nearly dark photo.
The ISO setting makes the camera being used more sensitive to light. Thus, it allows your camera to take photos with a smaller level of light.However, in the case there was a lot less light present than you needed to record a photo. You had to do two things to get even a poor photo.
(1) You had to get MUCH closer to the stage.
(2) You had to get much closer to the stage and increase your ISO setting.
However, as I have said previously, with the camera you were using, you had to be no more than 12 feet from the subject of your photo to record an image. In imagining the situation, this was probably not possible. At least, now you know why your camera did not record a proper photo.