BY THE LOOK of things in the summer of 1949, the Weavers would never be heard of, or from, again.

No one would have predicted either their commercial success or the fact that it would lead to their downfall in the anticommunist hysteria of the time. Who would have guessed, too, that this would lead ultimately to the folk revival that began in the late '50s, evolving into the protest music of the early '60s, and spawning children ranging from Joan Baez and the Kingston Trio to Peter, Paul and Mary, Bob Dylan and Phil Ochs?

In 1949 the natural audience of the brand-new quartet was what used to be described as the Left, or political progressives. They were watching a post-World War II tide of anticommunism and antiunionism sweep the country, and chose not to gather too publicly.

The group included Pete Seeger, a Harvard drop-out who had made something of a name for himself in labor circles; Lee Hays, a tubby bass singer and writer of labor songs (he and Seeger were dubbed the Laurel and Hardy of the Left); Ronnie Gilbert, a voice student and secretary who loved folk music; and Fred Hellerman, just out of Brooklyn College (he and Gilbert had first met at a left-wing summer camp).

That summer of 1949, they lucked into an engagement at New York's Village Vanguard nightclub.

The audience started growing, record deals were struck and the Weavers became what they probably least expected--a huge popular success. Their records were admittedly tame, but their live performances bubbled with what one writer described as "symbolic, encoded music that reminded the Left of its existence: calypso, peace, topical songs." Of course, the Right broke the code pretty easily and it was stormy sailing from then on.

Hays and Seeger, along with Woody Guthrie, had been part of the leftist and ill-fated Almanac Singers, who played largely for the labor unions and the disenfranchised of the early '40s. The Weavers, however, came to represent something else, at once commercial and groundbreaking. Essentially, they simplified folk music, taking it out of the archives and slipping it onto the airwaves, thus making it accessible to large audiences, even if this brought on the wrath of the folk purists.

In 1950, the Weavers' string of hits began with a waltzy version of Leadbelly's "Goodnight Irene" and continued with "Tzena Tzena," "On Top of Old Smoky" and "Kisses Sweeter Than Wine." It all came to a crashing halt in 1952. Just as the Weavers were about to sign for a network television series of their own, Seeger, Gilbert and Hellerman were denounced as Communists by an informer. The news was headlined in publications such as Counterattack and Red Channels, which agitated for exposure of the "red menace" wherever it might be found. The series was quickly dropped, jobs were canceled and controversy began to dog the group like tomorrow's shadow. As Hays has said, "The blacklist forced us to take a sabbatical that stretched into a Sundical . . . a Mondical . . . and a Tuesdical."

Although the Weavers regained a large part of their popularity after a 1955 Carnegie Hall concert, they were still kept off television and radio. Seeger left the group in 1957. There were occasional reunions until the final breakup in 1963.

"Wasn't That a Time!," a wonderful documentary about the Weavers opening today at the West End Circle, is much more than an evocation of the quartet that introduced America to its own musical folk traditions. It's also a film about the getting of wisdom, the maintenance of spirit, the giving of hope and the joy of holding on to one's convictions.

Having survived both McCarthy-era blacklists and shifting tastes in pop music, the Weavers seem stronger in the telling of their story than when they lived it.

Carnegie Hall serves as a frame for the film. It was a 1980 reunion concert there, in turn inspired by a summer picnic attended by the principals, that suggested to director Jim Brown that the story of Lee Hays, Pete Seeger, Ronnie Gilbert and Fred Hellerman could be told, both for a new generation removed from Weavermania and for those who grew up with the group's amiable left-wing commitment.

Despite the ravages of time and the lengthy separation, each Weaver seemed to slip back into the whole cloth, rough-cut harmonies intact, spirits unfrayed.

Not that there wasn't doubt about the project: "I'm Lee Hays, more or less," grumbles the 74-year-old bass voice, referring to a double amputation due to diabetes but also suggesting individual concerns about trying to recreate a vivid history. Beset with medical problems (including a pacemaker), Hays hadn't sung for 10 years, but he spent months singing along to records, rebuilding his bass lines so that things would be "right." His irrepressible wit keeps the film from degenerating into a eulogy.

Another Carnegie Hall concert, 25 years earlier, had brought the group back to prominence after their near-demise during the '50s anticommunist inquisition. Some may be astounded that such inoffensive music could have caused such an uproar (in fact, the roar had little to do with the music, but with the musicians) but there always was a political current coursing through the ballads, labor and struggle songs from many lands that made up the group's repertoire from the time they first came together in the late '40s.

Much of this history is recounted in "Wasn't That A Time!" through judicious use of television kinescopes, newspaper clippings and mercifully few testimonials from Arlo Guthrie, Mary Travers, Studs Terkel and Harry Reasoner. In building to the climactic concert, director Brown remains rooted in warm memory, not cold archivism. As Ronnie Gilbert says at one point, "We felt that if we sang loud enough and strong enough and hopefully enough, somehow it would make a difference." Of course, it did. Brown also uses a clever montage technique to celebrate "If I Had A Hammer," a Seeger-Hays song that didn't catch on for the Weavers but did for an awful lot of others after it helped establish Peter, Paul and Mary.

The singing in the film is lovely, somehow exuberant and understated at the same time, whether it's on the Carnegie Hall stage, in Hays' backyard during a picnic, or the sunlit kitchen where the Weavers ended up rehearsing. Particularly moving is a political lament by feminist songwriter Holly Near, who teaches it to Gilbert in a loving sequence. A highlight of the final concert, it proved that even in remembering the past, the Weavers felt a need to touch on contemporary issues. But mostly, it's living-room music--friendly, with different voices taking the lead but the purest strength coming in the easy harmonies. Maybe that was the Weavers' ultimate message.

Perhaps more importantly, the film confirms four lives well lived. The famine-thin, but harvest-hearty Seeger may be the best-known figure, and his serene optimism is continually inspiring, but he in no way dominates the proceedings. Hays, feisty despite his condition, remains wonderfully funny. (He gets the last word in, too. After his death, his ashes are mixed into his beloved compost pile). Gilbert, a large, jovial woman with a larger voice and unbounded warmth, is somehow still in the process of discovering herself, and that searching casts a radiance whenever she is on the screen. Hellerman seems scholarly, almost rabbinical, but he's still a full quarter of the four-person heart beating so proudly again. We should all age so well.