When using the terms “left” and “right”, I shall use the convention of speaking from the viewpoint of the observer.
A few more facts emerge from the Wikipedia entry. The venue was Hyde Park, and the subjects are said to have been “bleary eyed after a party”.
On the front row, the chap with a folder under his arm is Andy Fraser; to the left of him is Paul Rodgers, and to the left of him is Simon Kirke. These are, of course, respectively, the bass player, vocalist and drummer with Free. The compiler of the picture had great prescience in putting these guys to the fore, as the band would turn out to be the most successful of the lot. Conspicuous by his absence, however, is the guitarist Paul Kossoff, who would be dead within the next decade through drugs.
However, arguably the most prominent figure in the photo is the man behind and slightly to the left of Paul Rodgers. This is Ian A. Anderson; what on earth was he doing there? More of my puzzlement in the next post.