Tortoise doesn't inspire such demonstrative behavior. Rather, its music is like a stylish end table; it adds a subtle finishing touch to a room. It's an accoutrement to an intelligently decorous lifestyle that prizes functionality over frills, thoughtfulness over passion, calm over rage. To some, Tortoise is the epitome of cool; to others, the Chicago quintet manufactures introverted jam-band noodling for record-store clerks.

But there's no disputing the impact that Tortoise's five albums have had on nonmainstream music since the group released its self-titled debut in 1994. Populated with versatile, intuitive players -- John McEntire (drums, vibes), Jeff Parker (guitar), Doug McCombs (bass), Dan Bitney (percussion) and John Herndon (drums, vibes) -- Tortoise possesses the sort of telepathic, egoless interaction that made Krautrock deities Can such a mesmerizing force. While it would be hyperbole to say Thrill Jockey's flagship band is an Americanized version of Can, it's not overstating things to note that the underground's sonic vocabulary would be more anemic without Tortoise's poised presence.

The band's well-considered eclecticism embraces Can's metronomic grooves, Ennio Morricone's wide-screen wistfulness, Indonesian gamelan, '70s jazz-fusion virtuosity and King Tubby's dubwise use of space. These influences are assimilated so deftly, no seams show. It all makes Tortoise the definitive post-rock unit -- although the band despises the term "post-rock," a genre whose cachet has waned over the last five years. Simply put, Tortoise employs rock's usual arsenal of instruments (plus lots of vibes and marimbas) to stretch the genre's parameters the way Ruben Studdard stretches waistbands.

If you need one track to summarize Tortoise's style, go directly to the 20-minute "Djed" off 1996's Millions Now Living Will Never Die. Here the group flaunts its gift for understatedly beautiful melodies and rhythmic surprises, its affinity for unusual textures (organic and synthetic) and resonance with Steve Reichian minimalism. It's a breathtaking aural journey, a brilliantly multifaceted gem. If only Tortoise's members could talk about their music with the same thoughtful depth with which they create it. Alas, we must instead present exchanges like this:

Can you discuss the group's creative process and dynamic regarding the new album, It's All Around You? Did it differ from past albums?

John Herndon: "Not really. We just came in and started writing songs. That's pretty much how it's always happened."

Everybody contributes in equal proportions?

"We all pretty much contribute equally."

Did It's All Around You come easier than past albums? Is the process becoming more streamlined and efficient?

"No way. It's definitely like pulling teeth sometimes, which is fine."

What situation would cause that sort of conflict?

"There's no real conflict among band members. It's more the conflict is within a person individually. For me, it's often like pulling teeth trying to write a melody line, but that's one of my roles in the band, because I play a melodic instrument sometimes, like the vibraphone or the marimba. I think my strength lies in being the drummer, [but] I have to force myself to come up with something in front of four other extremely talented musicians. I find myself getting frustrated sometimes, trying to come up with a part that I think would be interesting to myself and the other cats in the band."

Still awake? Good. The question is whether you will remain so while listening to It's All Around You. After a few spins, you may conclude that Tortoise has become a Muzak version of itself. But give the disc more time, and it'll coyly reveal its hidden charms. "Dot/Eyes" brings much-needed anger and energy; its stalking bass line and gunmetal-blue guitar squalls form a predatory brand of funk recalling Tortoise's contribution to Mo Wax's Headz 2 comp, "The Source of Uncertainty." The vibes-led prog-rock of "Salt the Skies" achieves a head of steam from McCombs's surging bass. And on "The Lithium Stiffs," guest Kelly Hogan coos diaphanous ahs and ohs like My Bloody Valentine's Bilinda Butcher over music that percolates and drones with somber intent. It's the group's first use of vocals in 11 years of recording.

"It turned out to be one of the most difficult recording sessions I ever did as a hired ninja," Hogan reports. "Partially because I think these guys are great musicians, and I was kind of nervous at first. It was an hour or two in a booth, quickly memorizing a tiny snip of arrhythmic melody, and then immediately unlearning that and learning the next piece -- over and over. It was some arduous tonal memory, and how.

"[When] I finally heard the quilted-together result a few months later, I was blown away. It sounded like a $200 haircut or a complicated machine that makes something tiny and intricate and delicious."

Another outsider, departed founding member Bundy K. Brown, contributes further enlightenment: "[There] is a level of idiosyncrasy to the group's approach and vision that arises from the sort of interplay that any musical group has, but is obviously unique to them as an outgrowth of their personalities and individual talents. I've always gathered that the overall approach has changed little since I was in the group [Brown left in 1995]: No boundaries, keep challenging yourself and one another -- and the product of that is going to be some good music. I think all the Tortoise recordings…are in keeping with that. Tortoise is the sort of group that is both going to encourage discussion and make that discussion difficult, in that they defy easy categorization by transcending the accepted genres and subgenres we're all familiar with, and because there is neither an explicit nor implicit narrative in their music."

Bundy nailed it. Go buy his releases with Gray Market Goods, Pullman and Directions in Music.

As for Herndon, one of Chicago's most in-demand drummers, he can look forward to his bartending gig when Tortoise completes its world tour. Shocking but true.

That's not really a good use of your skills, John.

"Ha ha. I'm a good bartender, man."

Are you a better bartender than you are a drummer?

"I do it more often."