Ask Tortoise drummer/programmer/producer John McEntire the difference between a turtle and a tortoise and he answers with a question: "The tortoise is larger?"

But ask him if he thinks that instrumental music is off-putting to fans and the answer you get is far from waffling. "Really? I find that hard to believe," McEntire says succinctly. Keyboardist/drummer Johnny Herndon echoes the sentiment: "I think that's ridiculous. I mean, nobody ever freaks out that there's no words in jazz." Herndon concedes that maybe it's a hair more difficult to get into music that you can't sing along to on a "I feel so sad-I feel so happy" level. But, ultimately he retracts that thought and concludes "That's just completely not true."

What is true is that Tortoise, now touring Europe to support their ambitious third release, TNT, are experiencing a popular and critical groundswell of interest. The Chicago band is playing to sold-out crowds, and will be returning to the States at the end of this month to kick off a tour here. There's a steady demand for their records in street-cred stores across the States, Europe and Japan. Industry bible Billboard examined their phenomenon in a recent issue. Rolling Stone reviewed the record (four stars, no less). In sum, if instrumental music is more difficult to grasp than Hootie and Hanson, there's no shortage of ambitious listeners eager to be transported by Tortoise's inventive and baroque songcraft.

TNT, like the group's self-titled '94 debut and '96's Millions Now Living Will Never Die, is a cinematic blend of ambient noise, south-of-the-Equator rhythms, murmuring subsonic bass and carefully placed guitar flourishes. Whereas the first two records were completed in two to four weeks, TNT was a much more time-consuming and detail-oriented affair. Abandoning the warm, pleasantly muddy analog sound of their prior efforts, Tortoise spent nearly a year twiddling and fiddling with state-of-the-art digital recording gear. The result is a dense and intellectual collection of songs whose themes -- and sheer brilliance -- are revealed slowly over repeated listening. Melodies and hooks not initially apparent emerge from the lush soundscapes like errant wisps of smoke.

"We barely played together at all during the making of the record," McEntire says. "This decidedly different approach was more a matter of circumstance rather than a pre-meditated idea to work in a particular way."

Herndon believes the process taught everyone in the band (now comprised of six multi-instrumentalist members: the two Johns plus Douglas McCombs, Dan Bitney, Dave Pajo and newest addition Jeff Parker) a thing or two about making records. "We didn't really have any goals set out other than to try and make a good record," he recalls. "I think that maybe the next record we make will be back again to recording on tape and playing more together as a group. We'll try and find a balance between a lot of studio technology and playing more together."

Of course, playing as a group is easier said than done in a band like Tortoise. All the band's members are involved in side-projects ranging from full-fledged bands to guesting on records to producing gigs. McEntire, for example, is the timekeeper (as in drums, not clock-puncher) for the Sea and Cake, who have four records on indie label Thrill Jockey -- Tortoise's home, as well. He has also recently scored a film and has engineered for the likes of Stereolab and Trans Am. Together, the members of Tortoise can be linked at one time or another to those bands plus the Red Krayola, 5ive Style, Uptighty, Rex, Eleventh Dream Day, Poster Children, Gastr Del Sol, Bastro and on and on.

"It does lead to a bit of schizophrenia," says McEntire. "Which I quite enjoy."

As evidenced by the diversity represented in the above list, McEntire is quick to point out that Tortoise's unconventional lineup doesn't mean he's a musical one-trick pony. "I wouldn't necessarily say that one set-up should be considered superior above others; it all depends on what you're trying to accomplish. I think people are getting a little more adventurous in their incorporation of instruments that are slightly beyond convention, and hopefully that will continue," he says. "I see that as an exciting and positive development. Then again, that's not to say there is necessarily anything lacking in a 'standard' Bass-Drums-Guitar set-up."

Yeah, but what about lyrics?

"If you listen carefully [to TNT], says Herndon, "there's a loop on one whole tune that says 'aw fuck' over and over."

Check out a clip of "Four Day Interval" in RealVideo: 28.8 or