John Flansburgh and John Linnell have tackled some squirmy subjects over the years. As They Might Be Giants, the duo has written and recorded songs about palindromes, purple toupees, people with delusions of minor-league grandeur ("She Thinks She's Edith Head") and something called a "Hide-away Folk Family." One of their modest hits was a track sung from the perspective of a nightlight ("Birdhouse in Your Soul"); another, "Istanbul (Not Constantinople)," was about the changeable nature of geographical names. But recently, the Brooklyn-based outfit has embarked upon some projects that have surprised their longtime fans, and some that have left even the band itself a bit stumped.

The most high-profile feather in TMBG's idiosyncratic cap has got to be their work on the award-winning Fox comedy Malcolm in the Middle. Not only is their super-infectious "Boss of Me" the theme to the show, but Flansburgh, Linnell and a handful of cohorts score every episode, every week. "It's kind of our day job," Flansburgh says. " … The show is insanely music-intensive. And I don't think we realized how draining it would be when we started. I think we thought it would be this very glamorous kind of gig. It's actually much more heavy lifting."

The brain trust has created a number of sonic libraries to coincide with the show's many moods and characters. They've got one kind of music for domestic scenes, one for chase scenes, and yet another to create the anxiety vibe that's inevitable on this dysfunctional family free-for-all. For scenes involving Hal, Malcolm's blundering, possibly sociopathic father, they use music based on that most psychedelic of instruments, the Mellotron. "We basically spent the last 10 years of our lives recording a half-hour of music every two years," says Flansburgh, "and now we record a half-hour of music every two weeks, so it's just a really different level of production. … It's not like you're sitting around waiting for inspiration to strike. It's more like, "OK, what's the bassline?' It's kind of like going to the graduate version of Rockschool."

It should be clear by now that TMBG are not simply novelty-song jesters of the alternative music court, as many may have once considered them to be. Brainy and prolific, the pair has been collaborating since they first became friends, working on the newspaper at their suburban Boston high school. They hooked up again in New York in the early '80s, after college, forming They Might Be Giants (the name comes from a 1971 comic adventure film, starring George C. Scott as a retired judge who thinks he's Sherlock Holmes) with Flansburgh on guitar and vocals, Linnell on accordion and vocals, and a drum machine. With a growing underground following but no record deal in sight, they began an oft-accessed Dial-a-Song enterprise. The service is not only still going strong some 15 years later (call 718-387-6962 and find out for yourself) but has a charming online version, www.dialasong.com.

Alternative distribution has paid off for the duo. The popularity of the original Dial-a-Song led to a deal with Bar/None, distributed by Restless; the band's latest ventures have recently led to a multi-album deal with Restless itself, now a subsidiary of BMG. One of these projects is www.tmbg.com, just one of the band's several remarkable Web sites. Though the pair don't design the sites themselves, they do choose the people who do. "We are very popular with the art department wherever we go," says Flansburgh. "Costumers, the scientific community, that's our demo."

But, by far, the band's loftiest undertaking of late has been a special Art & Music issue of the literary quarterly (and online daily) McSweeney's. TMBG were given material by McSweeney's editor Dave Eggers, and asked to "do something with it," recalls Flansburgh. The result is a 37-song CD that will come with the forthcoming issue, with each track inspired by one of the essays or art pieces in the issue. Two works by New Yorker staff writer (and biographer of Tampa's own J.S.G. Boggs) Lawrence Weschler, presented a particular problem to the duo. "He wrote these essays, two companion essays," Flansburgh explains, "one about women looking over their shoulders in art, and then he wrote this parallel essay about men looking over their shoulders in art. So everybody's kind of looking back, and looking at the viewer in this weird way. And he's just kind of reflecting on it — it's a very philosophical, art historical, theoretical essay. And trying to write a song about that is a very tall order, and we've written songs about a lot of things. But to write songs about some of this stuff is as theoretical as it gets." The Johns saved the Weschler essays for last, until Flansburgh finally found his Eureka: "It dawned on me, we'll just do things backwards."

The main line of distinction that TMBG seems to have crossed in the past year or so is the one between "interpreted" and "interpreter." In other words, instead of constructing semi-inscrutable songs for their rabid fans to try and wrap their heads around, TMBG has devoted much of their recent time to making sense out of other people's art. This line may have been traversed, or at least blurred, when NPR's This American Life commissioned the duo to pen a song for a piece that the nationally syndicated radio show was doing on the band itself — the result was "I'm Sick of This American Life." Since then, TMBG has recorded new theme music for The Daily Show with Jon Stewart and for a new all-animated, adult-oriented primetime series on the WB, The Oblongs.

"Everything we've been doing this year, the past couple of years," says Flansburgh, "it's really an interesting task to be out in the world and to be doing stuff, collaborating with people. But in some ways we're just kind of working for projects. It's just so different to write for something like that. … We've got to sort of figure everybody else out now."