Fifty years.

“You can’t get away from that number,” Keith Richards said with a chuckle by telephone from Paris, where the Rolling Stones have been rehearsing for arena concerts and have played guerrilla club and theater shows. The Stones, led by Mick Jagger and Richards (although the other members have changed), played their first gig in 1962. And with less than two months remaining in this anniversary year, the machinery of commemoration and promotion has swung into motion.

There are arena concerts scheduled in London (Nov. 25 and 29) and Newark, N.J. (Dec. 13 and 15). There is a new documentary (on HBO this week) and a new Stones song on the radio: “Doom and Gloom,” a Jagger song that mentions fracking.

In one way the Stones have been doing the same thing for half a century: playing obstinately unpolished rock ‘n’ roll.

A band that was once synonymous with a riotous volatility has become — despite all commercial, cultural and chemical odds — a symbol of stability. Members now describe the band with an unexpected word for the Rolling Stones: discipline. “It requires quite a bit of discipline to be a Rolling Stone,” Richards said. “Although it seems to be shambolic, it’s a very disciplined bunch.”

The guitarist Ronnie Wood, who joined the band in 1975, agreed. “No matter what was going on the outside, no matter how much we whooped it up,” he said, “we felt a responsibility, and we still do, to make great music.”

The Stones’ outlaw archetype is the through line of “Crossfire Hurricane,” a documentary that hurtles through the band’s first 20 years, which comes to HBO on Thursday. “They start off playing this role, they become the role, and then the role nearly kills them,” said the director, Brett Morgen. Yet eventually, as Jagger says in the film, the Stones change from being “the band everybody hated to the band everybody loves.”

“Crossfire Hurricane” draws on older Stones documentaries that now look startlingly candid. Early material comes from “Charlie Is My Darling,” Peter Whitehead’s documentary of a chaotic 1965 Stones tour of Ireland that found concerts regularly cut short as audiences stormed the stage; that entire film has just been released on DVD, along with crackling live performances from the same era. The youthful Rolling Stones are earnest, thoughtful and amused by the frenzy their performances set off.

“We were such nice children, underneath it all,” Jagger recalled.

The band is delving into its catalog for the upcoming concerts, but Jagger knows the audience expects hits. “I don’t want to be totally predictable, which is kind of hard when you’ve been doing something for 50 years,” he said. “It’s the Rolling Stones onstage. You know what it’s like. They do ‘Honky Tonk Women.’ They do ‘Satisfaction.’ People coming to a 50th-anniversary show want some kind of predictability.”

Richards pronounced himself “amazed” at the band’s longevity.

“There is a certain magnetic glue that pulls us all together, that overrides any other peripheral things,” he said. “Once we get behind our instruments there’s something bigger. The sum is greater than the parts. There’s just a feeling that we were meant to do this, we have to do this, and we’re just following the trail.”