NEW YORK -- Albert Maysles, the revolutionary documentary filmmaker who helped pioneer nonfiction movies by turning a keenly observant eye on both the famous and the ordinary in films like "Gimme Shelter" and "Grey Gardens," has died. He was 88.

In a statement, Maysles' family said the director passed away after a brief battle with cancer at his New York home Thursday night.

Maysles was best known for a handful of documentary classics he made with his brother, David, in the 1960s and 1970s. The Maysles Brothers -- as many referred to them -- chose subjects as ordinary as the struggles of Bible salesmen and as glamorous as Marlon Brando, Orson Welles and the Beatles, whom the pair followed in 1964 during their first trip to the United States.

One of their films, "Gimme Shelter," about The Rolling Stones' Altamont Speedway concert on Dec. 6, 1969, captured on film the killing of a fan and the darkening of the hippie dream. The Altamont concert was the Stones' disastrous effort to stage a festival like the Woodstock gathering a few months earlier.

Maysles was active right up to this death. His documentary of the fashion icon Iris Apfel, "Iris," is to be released in April. Earlier this week, the Tribeca Film Festival announced that "In Transit," a documentary he co-directed about the longest train route in the U.S., will premiere at this year's festival.

"We lost a true titan today, one who pioneered an art form and fostered a whole generation of artists," said Eamonn Bowles, president of Magnolia Pictures, which is releasing "Iris." "His impact is immeasurable and we won't soon see his likes again."

Born in Boston to Jewish immigrants from Eastern Europe, Maysles served in the U.S. Army from 1944 to 1946, studied at Syracuse and Boston University and taught psychology for three years before turning to film. His first foray into motion pictures was a 16-mm documentary he made in 1955 while visiting mental hospitals in the Soviet Union.

Maysles started out as an assistant to Robert Drew, a pioneer of cinema verite, and his peers included such acclaimed documentary makers as D.A Pennebaker and Frederick Wiseman.

He and Pennebaker were among those who worked with Drew on the groundbreaking 1960 documentary "Primary," about rival Democratic presidential candidates John F. Kennedy and Hubert Humphrey. Maysles also served as a camera operator for Pennebaker's 1968 concert film "Monterey Pop."

"My friendship with Al was forged during four months of filming together, just the two of us, in Russia in 1959," said Pennebaker, referring to their film "Opening in Moscow," about that year's world fair. "When he got a camera against his eye, he was one of the world's great watchers, and I knew we would always be filmmaking companions."

The Maysles and others worked without scripts, sets or lighting. The resulting works had no narration, no filmed interviews and gave audiences a fly-on-the-wall feeling.

"Our films aren't the conventional kind, locked down and scripted before shooting begins," David Maysles once said of their films. "We shoot life as it's lived."

A technical revolution had made such films possible -- the arrival of lightweight, portable sound and film equipment -- and gave them the opportunity to observe their subjects with as little effect on events as possible. "The natural disposition of the camera," Maysles said, "is to seek out reality."

In 1966, using the new equipment, they filmed Truman Capote shortly after he finished "In Cold Blood." Capote explained that his book was his idea of the "nonfiction novel" -- "a synthesis of journalism with fictional technique."

"We wanted to experiment in film the way Capote had experimented in literature," Maysles said in "Hand-Held and From the Heart," the filmmaker's autobiographical documentary. That led them to make the feature-length "Salesman" in 1968, following Bible salesmen from house to house as they try to convince people to buy what one of them calls "still the bestseller in the world."

The technique of unfettered observation -- "direct cinema," the brothers called it -- allowed the Maysles Brothers to record such historical moments as the slaying of a fan at the Altamont concert, and the grim reaction of Mick Jagger, the Stones' singer, as he watched a replay of the footage.

In "Grey Gardens," released in 1975 and later adapted into a Broadway musical, the Maysles Brothers captured on film the lives of a mother and her daughter, relatives of Jacqueline Kennedy Onassis, living in a falling-apart East Hampton mansion.

Some critics attacked the cinema verite techniques as falsely objective, given that the film ultimately viewed by audiences was usually a result of what the filmmakers chose to focus on and the cutting and selecting of the editing process.

"Any work of art is a combination of objective and subjective," Maysles once told The New York Times in response to those criticisms. "But I try to minimize my effect. I don't interview people, for instance. If you ask a question, that determines the answer. Making a film isn't finding the answer to a question; it's trying to capture life as it is."

After his brother died in 1987, Albert Maysles continued to work with various collaborators and mentored younger filmmakers. In 2006, he founded the non-profit Maysles Documentary Center in Harlem.

"While we mourn the loss of Albert, we also celebrate his remarkable life and hope that it serves as inspiration to people around the world to be willing to push themselves creatively and take the time to observe and reflect on life as it unfolds," said Erika Dilday, executive director of the centre.

Maysles also continued a longtime working relationship with artists Christo and Jeanne-Claude, whose process for creating monumental environmental art the Maysles Brothers documented in several films beginning in the 1970s.

They were Oscar nominated for their 1973 short "Christo's Valley Curtain." In 2007, Maysles and Antonio Ferrera made "The Gates" about Christo and Jeanne-Claude's Central Park project.

Last July, President Barack Obama awarded Maysles the National Medal of Arts, honouring his six decades of filmmaking. Said Obama: "By capturing raw emotions and representations, his work reflects the unfiltered truths of our shared humanity."