According to Wikipedia “He performed at Woburn Abbey on July 2, 1977, to an audience of 55,000 British fans. The concert and interviews were taped by film director William Friedkin, who used six cameras to capture the performance”
William Friedkin was the director of the French Connection and The Exorcist. French Connection won 5 Academy Awards including best director.
So quite obviously, the filming of the concert was in good hands. I just wonder why the entire was never released. I think fans would love to see it. Makes we wonder what happened? Any insight?