Just a hint of Abbey Road in this photo, no?
This was the site of the Expo 67. Note distance between stage and audience (already assembling), and between audience and PA (top of picture)
Detail of the above, shewing backline amps, monitors, grand piano, B3 with pedal-board, and so on
Who are these three people, we wonder. And is that a wah-wah pedal or an opened box of chocolates?
As above: front-on view of band set-up, with BJ's Funky Paul kick-drum skin: close up photo of this is here
Procol Harum dates in 1971