The road traveled by the Firesign Theatre to national television is so circuitous that not even the four members of the legendary comedy group know exactly how they finally arrived at PBS for Weirdly Cool, a one-hour special instigated and coproduced by Philadelphia's WHYY, where it premieres exclusively at 8 p.m. Wednesday.

"Ask the other guys," suggests Firesigner Phil Proctor. "I don't care how it happened. I'm just glad that it did, after 35 years."

Three of the four - Proctor, Peter Bergman and David Ossman - will appear live on WHYY to participate in pledge breaks during the premiere. (Phil Austin will seek pledges via videotaped segments.) The multilayered Weirdly Cool then repeats at 9:30 p.m. Wednesday, and again twice more late on Saturday, when it begins airing nationwide.

As it turns out, the four can't even agree on why they failed to achieve a national television breakthrough during their late-'60s and early-'70s heyday, when they earned critical acclaim for their complex, nonlinear, comedic "radio plays." Those bizarre records on the Columbia label - including How Can You Be in Two Places at Once When You're Not Anywhere at All?, I Think We're All Bozos on This Bus, and Don't Crush That Dwarf, Hand Me the Pliers - influenced a generation of comedians and earned the group cult status, but little else.

"Don't think we didn't try to get onto TV," Proctor insists. "Mainly, nobody would put us on. We were an ensemble group, counterculture comedians, expressing complicated ideas about American society at a period before cable TV became important. We tried a couple of pilots and approached all the networks, but they never had much interest."

Austin recalls it differently.

"It's not that TV neglected us, it's that we didn't want much to do with TV. We were too busy carrying the audio flag, dragging the concept of old-time radio around, kicking and screaming."

While contemporaries such as the Monty Python troupe found huge success after TV breakthroughs, the Firesigners were relegated to a few commercials, talk-show appearances, some cable improv work, and a couple of short films - but never had their own show.

Their TV fortunes changed, in large part, because two WHYY honchos, John Rice (who has since left the station) and director of broadcasting David Rubinsohn, were Firesign fans. When the group reunited after 18 years to record an original album in 1998 (Give Me Immortality or Give Me Death) and a second effort in 1999 (Boom Dot Bust), both for Rhino Records, the two men began talking to officials at Rhino's entertainment division about funding a PBS special. That plan finally came to fruition this year as WHYY and Rhino partnered to finance a taping of two live Firesign shows (later edited together) at the CBS Television City Studios in Los Angeles in August, just after release of the group's latest record, Bride of Firesign.

Finding a suitable TV format, however, was complicated, especially given the esoteric, audiocentric nature of the work.

"How to translate them?" Rubinsohn recalls. "[WHYY] felt their sophisticated humor and history would make them a good fit for us, but we wanted something that included their classic material, with a sort of Unplugged feel to it, in front of a studio audience. Our goal was to pull in both the older, educated crowd who remember the guys from their college days, and maybe a bit of a different audience from typical PBS viewers - younger people who are curious about the group."

Producers and the group settled on a format that comprises five scenes (a sixth is featured on the DVD/video version, which PBS stations will use as a premium during pledge breaks). The scenes originated on albums, were adapted for a handful of rare Firesign stage performances, then readapted for television.

In other words, no stand-up and no conventional sketches. Instead, the performances are a stew of readings, pantomime, sound effects, and stream-of-consciousness theatrical stagings of portions of their work, updated with contemporary references. With those performances, the show features rare, vintage film clips (including a bizarre car commercial the guys did in the '60s), and testimonials from Robin Williams, Chevy Chase, John Goodman and George Carlin.

"It's appropriate that we ended up on PBS, finally," Austin says. "After all, we started on public radio [in Los Angeles in the early '60s], and we're familiar with the concept of pledge breaks, which we'll be participating in. In fact, I think we probably did some of the first pledge breaks ever recorded, on radio in the '60s."

The show's centerpiece is a scene featuring Firesign39;s classic, befuddled and possibly delusional private eye, Nick Danger (played by Austin), performed old-time-radio style, with narrator and live sound effects by the four onstage.

"Defining the material and adapting it was certainly the most difficult part of this project," Ossman says. " . . . Ironically, we taped the special in August, prior to the events of Sept. 11. One of the pieces we included is the 'Parallel Hell' bit from Dwarf, which originally satirized the Korean War movies, and was later updated for the Vietnam period. Little did we know the nation would be back at war by the time this was broadcast."

The testimonials from Williams, Chase, Goodman and Carlin - all of whom cite the Firesigners as a major influence - play a crucial role. Bergman says that, beyond the "thrill" of having such well-known comic artists participating, their presence serves as a method of "extending" the Firesign39;s reach to a new generation.

"The big thing they do for us is place us in context for people who don't know Firesign39;s earlier work," Bergman says. "We feel our new albums, and this show, can stand on their own, even for fans who have not heard our earlier material. Having guys with their kind of mainstream reach citing us as influences, though, gives us the kind of cachet we are looking for."

The search for that cachet finally matters to the four men, now all in their early 60s and living on the West Coast, and suddenly serious about promoting "our investment in the Firesign Theatre," according to Bergman. Indeed, the opportunity to make what Proctor calls "a downright strange" emergence into the consciousness of a new generation of fans via PBS was too good to pass up. It's one of the many ironies surrounding Weirdly Cool.

The biggest irony, though, is the fact that the show exists at all. After all, this is a group whose members drifted apart in the '80s to launch successful individual careers as radio, TV, feature-film, stage, and voice-over actors. Then, in 1998, the four suddenly returned to their esoteric audio art form, and finally earned this TV opportunity. They've been flooding the marketplace with Firesign product ever since - in fact, more than ever before.

Besides Weirdly Cool and Bride of Firesign, the group recently started the Firesign Records label to release the group's vintage niche recordings, signed a deal with Columbia to rerelease its classic albums, started a radio show on the new XM satellite radio service, and is planning a theatrical tour for 2002.

Such developments have made the Firesign Theatre "mature overnight sensations," Bergman says. So Weirdly Cool could end up being either an appropriate exclamation point to the members' long history as comedic iconoclasts or the start of a new chapter in a strange journey - or both.

"We just waited 35 years to start promoting ourselves, that's all," Proctor says with a chuckle. "These things take a while."