(FORTUNE Magazine) – Woodstock was one of the defining cultural moments of the mass-media age, and the mere mention of it therefore brings to mind some very specific imagery. When you think of Woodstock, you think of psychedelic music and psychedelic drugs. You think of dirt, mud, and rain. You think of naked hippies bathing in a pond. You think of free love. You think of...feminine protection?

That, apparently, is what the folks at Procter & Gamble have in mind, at least judging by a remarkable new commercial for their Tampax brand, the leader in the $706 million tampon category. The 30-second spot, which began airing in March, shows a series of Woodstock scenes--including, sure enough, naked hippies bathing in a pond--set to the tune of "Time of the Season" by the Zombies (suitably evocative of the era, although the Zombies didn't play at Woodstock). There's no hint of what the ad is selling until the very end, when a young woman is shown dancing in the rain and the following words appear onscreen: TAMPAX WAS THERE.

It's hard to argue with this assertion, since some Woodstock attendees no doubt had Tampax tucked away in their leather satchels. But the ad seems like an unusually poor match of product and image. I mean, given all the dirt, mud, free love, and drugs, Woodstock might charitably be described as being somewhat less than ideally hygienic, if not downright unsanitary--not exactly the sort of association you'd think a marketer would want for this product.

Understandably, Tampax brand manager Bill Pearce doesn't see it that way. "We chose to focus on the fact that Tampax enabled people to attend Woodstock," he explains. "Prior to the invention of tampons, many women couldn't have attended, because you couldn't do some of these things wearing pads." The notion of tampons giving women the freedom to play tennis or go hiking is a well-established and legitimate marketing approach, and Pearce repeatedly stressed the brand's tradition of "empowerment" in this regard, but the activities at Woodstock are a curious choice for this type of appeal. As one female acquaintance of mine put it upon seeing the ad, "Apparently it was a lot easier to trip on acid and wallow in the mud without those bulky pads."

Feminine-hygiene products, of course, are notoriously difficult to market, and the Woodstock ad deserves credit for avoiding the category's age-old pitfall of squeamish language simply by dispensing with a script. It also goes admirably against the grain of P&G's legendarily staid ad style.

Still, you have to wonder about the demographics, since most of the women who attended Woodstock are now beyond their Tampax years. Pearce isn't concerned by that either. "It's not a generational ad," he says, casually dismissing one of history's most generationally charged events. "Woodstock speaks to transgenerational issues--it's about that freedom that's constant, regardless of generation." Okay, but given that many of the young women Pearce is trying to reach weren't even born when Woodstock took place, why risk the event's ridicule potential ("Can you believe anyone ever wore those clothes?") when more contemporary rock festivals like Lollapalooza and, especially, the woman-oriented Lilith Fair are available?

Such questions notwithstanding, "Tampax was there" is slated to expand into a major print and broadcast campaign designed to reinforce the brand's heritage. A second spot currently airing, which shows how Tampax has, uh, empowered several generations of coeds to frolic on the beach during spring break, is relatively straightforward, but it's the Woodstock connection that still fascinates on so many levels. Perhaps the ad's biggest irony lies in the widespread joke that millions of people now claim to have attended Woodstock, even though the actual crowd numbered about 400,000. Saying "I was at Woodstock," as Tampax is doing here, is now considered such malarkey that the standard response has become, "Yeah, sure you were." Still, as baffling as the ad is, it could have been worse--at least Tampax didn't align itself with Altamont.

PAUL LUKAS, author of Inconspicuous Consumption, obsesses over the details of consumer culture so you don't have to.