Some of Mr. Trynka’s account is not new, having appeared in “Stone Alone,” the often overlooked 1990 memoir of the Rolling Stones bassist Bill Wyman, or other books written by band outsiders. What makes Mr. Trynka’s book fresh and interesting, and gives it credibility, is the length he has gone to find witnesses to corroborate and elaborate on those stories.

It’s not just that Mr. Trynka has sought out those who worked with the band on the creative side, such as the singer Marianne Faithfull, the arranger Jack Nitzsche and the recording engineers Eddie Kramer, Glyn Johns and George Chkiantz. He has also interviewed those with more of a worm’s-eye view: drivers, roadies, office staff, old girlfriends and former roommates like James Phelge, whose surname the band would appropriate to designate songs that were group compositions rather than Jagger-Richard numbers.

“Brian Jones was the main man in the Stones; Jagger got everything from him,” the drummer Ginger Baker, who played in the band at some of its earliest shows and went on to become famous as a member of Cream, says in the book. “Brian was much more of a musician than Jagger will ever be — although Jagger’s a great economist.”

Citing those present at the creation, Mr. Trynka contends that Jones had a hand in composing some well-known Stones tracks, including “Paint It, Black” and “Under My Thumb.” He also claims that “Ruby Tuesday,” a No. 1 hit early in 1967, is actually a Jones-Richards collaboration — written not by Mr. Richards in a burst of inspiration and heartbreak in a Los Angeles hotel room, which is how the story is told in “Life” and elsewhere, but, according to Ms. Faithfull and Mr. Kramer, “labored over” by the pair in London for weeks.

“I used to say to Brain, ‘What on earth are you doing?’ ” Stan Blackbourne, the accountant for the Rolling Stones at their mid-1960s peak, recalls in the book. “ ‘You write some of these songs, and you give the name over as if Mick Jagger has done it. Do you understand, you’re giving ’em thousands of pounds!’ All the time I used to tell him, ‘You’re writing a blank check.’ ”

Mr. Trynka also looks into the circumstances of Jones’s death, on July 3, 1969, in the swimming pool at his home in East Sussex, once owned by A. A. Milne, but after all the Sturm und Drang that has come before, the subject is somewhat anticlimactic. In numerous books and in films like “Stoned,” it has been suggested that Jones was murdered, but Mr. Trynka painstakingly examines the flaws in each of the theories, and ends up close to the official verdict, “death by misadventure,” because of drug and alcohol consumption.

“The official coroner’s verdict on Brian’s death was perfunctory and lazy,” Mr. Trynka concludes. Nonetheless, “I’ve come to share their belief that Brian’s death was most likely a tragic accident” and to believe that “many of the existing theories that his death was in fact murder rely on unreliable witnesses.”

In the end, with the advantage of 45 years’ perspective, Mr. Trynka maintains, it is Jones’s music that matters. “It’s understandable why the survivors resent Brian Jones beyond the grave,” given his founder’s role, he argues, and also writes: “Brian Jones got many things wrong in his life, but the most important thing he got right.”