with his original plans for that show, which had been for just the Stones, the Who, and the SMALL FACES - with Steve Marriott, of all the frontmen Jagger wouldn't have wanted to follow if he was in his right mind. The idea of a rock and roll circus had been thought up by Mick, Pete Townshend, and Ronnie Lane of the Small Faces, But those plans fell apart, so they went with a different lineup except for the Who and, of course, the Stones.
The Who were very good. And the Stones did their set very late, when they were very tired. Filming all the acts had taken from two in the afternoon through five the following morning. And reportedly Mick was unhappy enough with the results that he didn't allow the show to be broadcast then and it wasn't released for 28 years.
But can you imagine if the Small Faces had been on it, with "All Or Nothing" and "Tin Soldier"? And their psychedelic album Ogdens' Nut Gone Flake had been at the top of the UK album chart for six weeks just months earlier.
I haven't seen anything about what happened to those original plans, whether the Small Faces didn't agree for one reason or another, or Mick changed his mind (came to his senses). Steve Marriott was becoming unhappier with the Small Faces, too, and quit just weeks after the Rolling Stones filmed their special. He didn't like their record label wanting more pop hits, and they couldn't reproduce that psychedelic album very well live, with just the four of them.
There's also another version of where the circus idea came from. The producer said he came up with the idea after drawing a circle on a piece of paper and free-associating from that, after first discussing the special with Mick. Personally, I think it seems more likely that Mick, Pete and Ronnie came up with the idea first.