TORONTO - When Canadian filmmaker John Walker was just 16 he faced an enviable career crossroads: either play drums with his Montreal band as the opening act for Frank Zappa in California, or start a job in a movie studio that same week.

An avid photographer, Walker took the film job that summer in 1969 and went on to helm several Gemini-honoured documentaries, including "Utshimassits: Place of the Boss," "The Hand of Stalin," and "Men of the Deeps."

As for the sticks, Walker gave them up and didn't touch them again until last year, while shooting his new doc, "A Drummer's Dream," in which world-renowned percussionists gather at an Ontario farm to teach 40 students.

"I didn't tell anybody that I'd been a drummer and finally in the last day in a jam session, the students ... brought up the sticks and I had to play. And I was intimidated like, beyond belief, with these world's greatest masters," Walker recalled in an interview.

"But when I played, it was like I slipped into this zone and it was like I couldn't believe how easy it was, and I finally realized: once a drummer, always a drummer."

"A Drummer's Dream," which is screening at Toronto's Hot Docs film festival, profiles seven master musicians as they come together to instruct and jam at a cottage-country camp in Westport, Ont.

Nasyr Abdul Al-Khabyyr, a Hull, Que., native who played drums with trumpet legend Dizzy Gillespie for six years, organized the gathering that also included Mike Mangini, billed as the fastest drummer in the world, and Latin conga great Giovanni Hidalgo.

Also there was Raul Rekow, Dennis Chambers, Horacio (El-Negro) Hernandez and Kenwood Dennard, all of who have drummed with big names including Gillespie and Carlos Santana.

"These guys are like absolute top of the game," said Walker, who lives in Halifax. "They're not known to the general public but ... they are absolute masters."

The doc, co-produced with the National Film Board of Canada, was shot at a former YMCA camp that Al-Khabyyr shares with 20 families. Cameras capture the instrumentalists tuning their drums, jamming, and sharing their insights and memories in front teenaged and adult pupils.

Scenes often play out with little editing or cutaways, and drummers will relish the uninterrupted shots of the masters pounding away on their kits, occasionally stopping to discuss their thought process.

"When I saw Mike Mangini's drum set being set up, it was like a Rolls-Royce," said Walker. "I sat down at the set, and I picked up a pair of sticks which I hadn't touched in, like, almost 40 years and I went, tap, tap, tap, put the sticks down and walked away from them.

"It was like sitting in a Ferrari and not turning on the key."

Many of the featured musicians hadn't been to Canada before, let alone the wilderness, and got a kick out out of the setting, said Walker.

"Their performances took place in a great big old, 19th-century barn -- perfect acoustics for drumming.

"Giovanni Hidalgo, who's based in L.A., gave me a big hug and said, 'You can't get acoustics like this in Hollywood. I want to do all my recordings here."