In the half-hour long video clip below, the immortal Professor Longhair, pride of Bogalusa, plays at the Jazz Festival in Nice, France, a festival established in 1948 and perhaps the oldest "jazz festival of international significance." The video's YouTube page dates the performance as 1979, but captions within the video say July 1978.
The outdoor venue is Nice's Arenes de Cimiez, a Roman amphitheater dating from the second century.
Here's the set list, and the approximate time each song begins:
Props to the poster named "Apostrophe(')" on the forums at nojazzfest.com, who shared this video and identified the bass player as a "young and super hip" George Porter, Jr.