Charlie Watts has been described by both Mick Jagger and Keith Richards as the man that keeps the Rolling Stones together -- a consistent, grounding force without which the band would have long since sputtered or spun out.

Perhaps every band has a person like that.

What's so great about the Stones' drummer is the shy and unassuming quality he has carried with him as both a player and a presence while acting as engine for the biggest rock band in the world.

Watts isn't a rock star, he's a drummer. It's heartening to see him participate in as surreal a spectacle as the Stones without giving up that designation.

Frivolous as it sounds, one likes to think that naming Charlie Watts as your favourite Stone somehow says something about your own character, too.

It's telling that his bandmates insist that even with their 40th-

anniversary tour under way, the Stones will be 39 until this coming January, when they mark the 40th year of their final "original" member, Watts.

"There were always three irreplaceables in the band, and that was Mick, Keith, and Charlie," retired Stones bassist Bill Wyman says.

"Charlie was the perfect drummer. He was brought up with jazz and he could swing, which is why I enjoyed playing with him so much.

"Charlie is a great catalyst. He always was between the two alter-egos of Mick and Keith, and the quietness of me and him. We were laid back and happy to go along. That's why the band stayed together so long."

Wyman points out that he and Watts were often termed "the greatest 'straight' rhythm section in rock 'n' roll because neither of them partook in the chemical excess their band was famous for.

"I'm very proud of that," the bassist says. "But I knew that when I left it wouldn't make any difference to the band. They could always find another bass player who could play along with Charlie. The same applied if Woody left. It was the same with Brian and Mick Taylor. If Charlie decided not to go on tour, there wouldn't be a tour. They wouldn't find another drummer to do it, I'm sure."

Charles Richard Watts was born in the London's Islington district on June 2, 1941, the son of a British Railways truck driver. His earliest memories were of German bombs exploding around his neighbourhood while his family rushed to the air-raid shelter. "War was something of a game to me, and I don't think I ever really and truly got frightened," Watts recalls with characteristic calm in Wyman's book Stone Alone.

Watts embraced visual art while growing up in the suburb of Wembley in the '50s and later attended the Harrow School Of Art before getting work at an advertising firm. He was a skilled footballer and cricket player, and he took up percussion at 14, after becoming so frustrated with his banjo he dismantled it and turned it into a drum.

He started playing with respected London musician Alexis Korner's Blues Incorporated in 1962. That led to an introduction to Brian Jones, and an invitation to join the Stones at the start of the next year.

The low-key jazz fiend "seemed a very unlikely candidate for a rock 'n' roll drum chair," Wyman later wrote. "Brian saw in Charlie, though, what (Brian) had in abundance and demanded from any musician: Commitment and idealism."

Significantly, Watts met his future wife, Shirley, around the same time. They married in 1964 and remain together.

Wyman still holds his close friend in high moral esteem.

"We both had children very early on," he says. "It's a bit to do with trying to live a normal life outside the mayhem and the lunacy, which can be very destructive."

Watts has enjoyed a concurrent jazz career with the Charlie Watts quintet and has dabbled in big band with the Charlie Watts Orchestra.

He has managed to exist below the media radar for much of that time. For instance, Rolling Stone magazine reported in the '90s that the drummer had a brief heroin habit in the '80s -- developed, apparently, while battling depression and loneliness while on tour -- not that anyone seemed to notice. The same piece described Watts' therapeutic habit of sketching the interior of hotel rooms.

Even during the group's rehearsal stays in Toronto, Watts prefers hotel rooms over rented mansions, unlike his bandmates. "I don't like leaving home, never have done," he says in the current issue of Mojo magazine. "But you can't be in a band and not play."

As for traveling with an entourage? "I hate to have people around me, except my wife and daughter."