Woodstock and Altamont. These two music festivals occurred within less than four months of each other, but they summon wildly different images: the former, the apotheosis of the Flower Child generation; the latter, the death of the counterculture, the archetypal loss of innocence. As journalist Michael Lydon summed up in his brilliant Ramparts article, "At Altamont in December, the dark side snarled its ugly answer to Woodstock's August joy."

Altamont, which took place on December 6, 1969, is remembered with infamy not only because four people died there -- people died at Woodstock, too -- or even because one of them died in anger. From a sociological perspective, Altamont was a moment when the counterculture attacked itself. It was a countercultural civil war.

Throughout a year that witnessed People's Park, the Harvard Student Strike, the Stonewall Riots, and the Days of Rage, violence and unrest had marred a number of rock festivals and performances -- from Denver Pop to Newport Jazz (which featured for the first time rock acts like Led Zeppelin and Jethro Tull) to Blind Faith's U.S. debut at Madison Square Garden. But in the Edenic woods of Bethel, New York, that August, young people had staged their own relatively peaceful happening. The biggest success of Woodstock was in showing that such an event could occur at all.

Hailed as "Woodstock West," Altamont would be anything but. And whereas most of the face-offs at earlier festivals had occurred between concertgoers and cops -- between "hippies" and "the man" -- the absence of law enforcement at Altamont quickly turned into lawlessness. Suddenly, the crowd members who flashed peace signs during moments of violence throughout the day were directing them not at the masters of war, but at each other.

In explaining a spontaneous environment that produced one fatal stabbing, three accidental deaths, and (by one report) 850 injuries, commentators have pointed to many reasons: Widespread drug use. The presence of the Hells Angels. Ad-hoc planning as the Rolling Stones road circus scrambled to move everything to their last-minute accommodations at Dick Carter's Altamont Speedway after being denied by Golden Gate Park and then Sears Point Raceway. (Pity Dick Carter, who kindly donated use of his property in exchange for what he thought would be good publicity.)

But there were drugs (lots) and Hells Angels at Woodstock, too. And that festival was also quickly thrown together after being kicked out of the inn: first by its namesake village and then by the town of Wallkill. Co-organizer Michael Lang, whose services were also enlisted for Altamont, and his crew didn't even have time to get the fence finished for Woodstock.

So what went wrong at Altamont?

Part of the problem was in the surroundings themselves. In contrast to the green world in Bethel, New York that summer, the barren hills at Dick Carter's Speedway in early December more closely resembled the nightmarish environments of underground artist Ron Cobb. David Dalton described the scene as "apocalyptic" and "unimaginably appalling, a mini Vietnam of garbage and old car wrecks." Spencer Dryden of the Jefferson Airplane said: "It was just a horrible, pink-sky Hieronymus Bosch dustbin, not a tree in sight, just a hellhole. It was the beginning of the end. No, not the beginning, it was the end." It was not a happy place.

The stage design also did not help. "The concert's like the proscenium of a theater. It's like an excuse for everyone to get together," Mick Jagger had said on the eve of Altamont. And get together they did. Crew members, hangers-on, and Angels all surrounded the musicians during their sets and created a sense of pandemonium throughout the day. But whereas the natural amphitheater and high stage at Woodstock had, for the most part, protected the performers from the crowd, the short stage at Altamont practically invited the crowd up front to try and get past the Hells Angels and at the performers.

The mood at Altamont was different, more sinister. In contrast to the Hog Farm's "please force" at Woodstock, the scene at Altamont was policed by the Hell's Angels Motorcycle Club. While unofficial Woodstock emcee Chip Monck had delivered his famously gentle warnings about bad acid making the rounds, Stones road manager Sam Cutler told one concerned concertgoer at Altamont looking for him to issue similar warnings: "Tough shit."

Did Cutler and the Rolling Stones pay the Hells Angels $500 worth of beer to police the stage, as was rumored immediately afterward (but denied by both sides)? Really, the question is moot, as the Angels were allowed, either by design or default, to surround the stage and act as muscle. ("You need people like the Angels to keep people in line," Grace Slick said on stage -- moments before Marty Balin jumped into the pit to break up a fight and was knocked out by the Angels.) Stanley Goldstein, collaborator on the Gimme Shelter documentary, recalled that Bay area Angels had traditionally occupied the place around the tech equipment or generators, and had established a secure location just by their presence, often in exchange for beer. But that was in a music scene dominated by trippy jam bands like Jefferson Airplane, Santana, and the Grateful Dead. Despite the presence of these same area bands on the Altamont bill, "Woodstock West" was, essentially, a Rolling Stones concert. Absent from the more trippy and rustic atmosphere at Woodstock, the Altamont headliners had brought a distinctly different vibe to America in 1969.

It was their first U.S. tour in three years, and demand for tickets to what Robert Christgau would describe as "history's first mythic rock and roll tour" had run high. Stanley Booth reflected, "Up until then their performances in the U.S. had been brief, incandescent explosions of desecration, attended almost exclusively by shrieking adolescent girls." But in '69, their fans were older and the group's music more angry. "As Tears Go By" and "Ruby Tuesday" had given way to "Street Fighting Man" and "Sympathy for the Devil." Booth describes the scene just a week earlier at Madison Square Garden: "It was a phenomenal crush. It started with a crush toward the front of the stage that you would have normally expected near the end of a concert, and then it simply grew from that." "In America in '69," guitarist Keith Richards later remembered, "one got the feeling they really wanted to suck you out."

With music fans in 1969 no longer content to be passive spectators at rock shows, it didn't help that the Hells Angels drove through the crowd and positioned their shiny bikes between the stage and throngs of stoned hippies. Goldstein also theorized that the Angels who first showed up were pledges and newer Angels eager to look tough. Boozed up, armed with pool sticks, and (as documented in journalist Nick Schou's forthcoming book, Orange Sunshine) unwittingly drinking red wine dosed with a brand of acid spread by the so-called "Hippie Mafia" from Laguna Beach, these Angels were a different cop than the more "genteel" Angels whom the Stones remembered from their Hyde Park concert that summer.

This was the equation then: Angels and hippies and Stones and booze and pills densely packed in a setting that hinted at the end of the world -- a combustible setting. And the ugliest incident involved Hunter, a black man who got into a scuffle with the Hells Angels, drew a pistol, and was stabbed to death by club member Alan Passaro as Hunter's white girlfriend, Patty Bredahoff, looked on in horror. (Passaro was tried for murder but pleaded self-defense and was acquitted.) Coming just two days after the death of Black Panther leaders Fred Hampton and Mark Clark in a controversial raid in Chicago, and as the nation was just beginning to learn about Charles Manson and his visions for an apocalyptic race war, Hunter's death would resonate with poignant racial overtones.

"Bringing a lot of people together used to be cool," said the Berkeley Tribe back then, "But at Altamont. . .the locust generation came to consume crumbs from the hands of an entertainment industry we helped to create. . . .Everybody grooved on fear." The underground journalists grooved on the fear and helped create the infamy of Altamont. In an article titled "Rock & Roll's Worst Day," Rolling Stone magazine would lend demonic overtones to the incident by reporting (erroneously) that Hunter was killed during the performance of "Sympathy for the Devil." The magazine's description of the scene rendered it into something out of the Dark Ages: "Flickering silhouettes of people trying to find warmth around the blazing track reminded one of the medieval paintings of tortured souls in the Dance of Death." In Ramparts, Lydon concluded, "We all seemed beyond the law at Altamont, out there willingly, all 300,000 of us, Stones and Angels included, and on our own."

Left on its own at the end of the decade and seemingly gathered at world's end, the Altamont congregation straddled the line between freedom and anarchy and experienced the ugly underside of a generation's collective dream.

Rob Kirkpatrick: The Day the Music Died? The Altamont Free Concert, 40 Years Later