What is the significance of the parental advisory sticker that’s firmly attached to Shoes for Industry!, the Firesign Theater’s new greatest-hits CD? After all, the stickering-album concept was almost unthinkable in the do-your-own-thing-man late ’60s, when many of these routines were written. Founding Firesign Peter Bergman explains the warning’s purpose: “It means that children should advise their parents to listen.”

Good advice from the typically contrarian comedian. Of course, many of today’s concerned moms and dads should well remember Firesign: four sage surrealists (Bergman, David Ossman, Philip Proctor, and Phil Austin) whose 20 albums of densely packed political parody and social satire offered a hipster’s color commentary on the culture and counterculture. That commentary became codified as nearly each turn of phrase from TFT’s sketches seeped into the daily lingo of collegians who inhaled. Entire albums would be memorized and repeated—repeatedly.

Says Ossman: “That’s the thing that thoroughly pleased me about the Firesign experience…that we would have put so many phrases into usage.”

It was “headphone comedy” of a kind not heard before or since. Its genius is confirmed by the fact that so many of the observations still hold true, such as the theme of Firesign’s 1974 album, Everything You Know Is Wrong. That notion increasingly sums up the predicament of modern living and now finds its way into headlines. “Everything you know is wrong—about housing,” quotes Ossman, cheerily. “I have that clipped out of some central-California newspaper.”

Additionally, their punch lines have become prophecy. “All of a sudden, something that the government pulls off makes our material predictive,” says Bergman, citing their 1980 Fighting Clowns. That album depicts “American soldiers dressed as clowns landing everywhere in the world. Which,” notes Bergman dryly, “is what’s happening now.”

Inevitably, time’s arrow deflated the public’s desire for cerebral humor. The Carter malaise yielded to Morning in America, which gave rise to such ugliness as Andrew Dice Clay and Sam Kinison. Now, says Bergman, “There’s no comedy in rock ‘n’ roll. There’s no performed comedy by groups. Most of what you hear in clubs is extremely personal, doesn’t have a lot of political relevance, and isn’t very stretchy—doesn’t really stretch the mind and doesn’t stretch the concepts. And also it doesn’t question authority. Most comics do not question authority and as such are fairly useless.”

Playing with the Big Questions is Firesign’s seriously mirthful mission, and its performances are more theatrical than simple stand-up. “Firesign gives you a play, which you can return to. And it’s thick enough that you have to,” brags Bergman.

So thick that college courses have been constructed to study Firesign’s work. Lest one think that’s just standard Ivory Tower wanking and that the “Porgie & Mudhead” sketch is merely a silly take on Archie and Jughead comics, consider Ossman’s explanation: “Mudhead is a Hopi clown. The mudheads are these clowns who wear these big pots on their heads and run around and do jokes, these lewd, obscene jokes, and funny stuff at very serious religious gatherings in the Hopi community. By calling him “Mudhead,’ we’ve memorialized the Native American clown.” Similar subtext may not be gleaned watching Evening at the Improv.

It was the election of a boomer prez—signifying, according to Bergman, that “America was ready to laugh again”—that brought the vinyl-vaudeville group back together. “Halfway through the campaign I was certain Clinton was going to win and we were going to throw the fascists out of office,” Bergman says, seriously. (If this sounds like overwrought hippie-speak to cynical ’90s ears, consider that it was Bergman who coined the quintessential ’60s term, “love-in.”) If Bush had won, however, Bergman believes that Firesign “would probably not have re-formed. It would have been just too dismal.”

The Firesigns’ 25th-anniversary tour stops at the Warner Theater Friday, their first group appearance here in nearly two decades. Back then, D.C. “was spooky,” says Ossman, who expects that performing here in 1993 “will be a pleasure—when I trust it’s less spooky than usual—in our brave new society that we’re tying to create.”

However intellectual the material may be, in person the group embraces wacky hats and goofy props to sell their relentlessly pun-filled show. “We’re really writers out there performing our writings,” explains Ossman. “That’s what has touched people, I think. It’s funny and it’s prescient and it gangs a lot of things together all at once in a way that makes them implicit rather than explicit. The problem with us at the time was that we were too implicit, not too explicit. Ah, god, well….”

And so he returns to the topic of advisory warnings—and any conversation with TFT is endlessly circumlocutory. Bergman hints that the veep is a Firesign fan and makes this vow regarding the Sticker Lady: “If Tipper comes, we promise not to perform any of the material backwards.”