Bright, stationary, white light appears low to ground and then vanishes over outdoor concert in Atlanta, GA.While at a Bonnie Raitt/Lyle Lovett concert at Chastain Park Ampitheater, I saw out of the corner of my eye in the NW sky what appeared to be a low flying helicopter with a bright light on. I thought this was odd considering that it was in the middle of the concert. This caused me to look up and directly at it for futher investigation.What I and two other concert goers (sitting in the row in front of me) witnessed was a very bright, intense, circular white light. It did not emit a beam. It was restricted to the source. It was stationary. There was no sound and no other visible structure. 2 seconds after my full gaze was upon it, it completely vanished. I searched the sky for an explanation (i.e. other lights, planes, helicopters, etc.) but the sky was completely empty.Clouds were clearly behind the object, much higher above.