The life and times of late-Rolling Stones co-founder Brian Jones is the subject of a new documentary. Arena: The Stones And Brian Jones will air on BBC Two and BBC iPlayer on May 15th.

Director Nick Broomfield recalled to The Guardian running into Jones on a train back when the filmmaker was just a 14-year-old fan: “I was surprised at how friendly he was. . . I just remember thinking how very middle-class, well spoken, polite and accommodating he was. . . I was traveling to school and he was going back to Cheltenham, where he grew up.”

He went on to say, “That chance meeting with Brian Jones on the train has stayed with me, not least because, back then, he seemed to have everything going for him. He was young, charismatic, incredibly gifted, and an integral part of a group that would define the time more than any other apart from the Beatles. He epitomized that dazzling ’60s moment in many ways, which is so very different from now, and then he was suddenly gone. I can still recall the shock I felt on hearing the news of his death.”

Jimmy Page was friendly with Brian Jones and told us he was impressed by his virtuosity when Jones hired him as a session player for his soundtrack to 1967’s A Degree Of Murder film, which the Stones guitarist wrote: “Bit by bit it unfolded into what a wonderful musician he was. I mean, he was a really fine musician. And he could play instruments right across the board, y’know? I knew that he had done the recordings for the Pan Pipes of Joujouka — he went over to Tangier and did all of that. So, he was really a hip character.”

We asked Lindsey Buckingham what that classic early-era means to him as a Stones fan: “The peak for Brian Jones, before he kind of started to slide downhill. . . Y’know those albums, I mean, the singles — everything — have a kind of European influence. But, y’know, the fact that Brian Jones as a bandmember could articulate that it in a different way and was more of a multi-musician and could bring in colors and influence the band in what I thought was a very positive way. Those albums are some of my favorite Stones albums.”

Brian Jones, who was forced out of the Rolling Stones on June 8th, 1969, died the following July 3rd at the age of 27. He was found dead at the bottom of the swimming pool at his Cotchford Farm home, in Hartford, England.

For years there have been conspiracy theories about what went on the night Jones died, including several suggesting foul play.