CHICAGO -- The door to Pumpkinland opens. Smashing Pumpkins leader Billy Corgan asks who has come knocking. I tell him, and he gestures for me to come inside the warehouse-turned-rehearsal-studio that is the group's base of operations.

"We're a little behind schedule," apologizes Corgan, who is dressed all in black.

Inside, in the front lobby, sit Pumpkins guitarist James Iha and bassist D'Arcy on a slightly frayed green velvet couch, wrapping up an interview with a local reporter. Shutting the front door, Corgan leads me through the lobby and another doorway, into the large rehearsal room. This is where, in a few hours, the Pumpkins will feel their way through a lengthy set packed with songs off their daring new album, Adore (June 2), as they prepare for an upcoming European tour and a "rumored" local club date. The set list also includes older work from previous albums including, of course, their 1995 smash, Mellon Collie and the Infinite Sadness. And at least one unexpected cover, the Band's "This Wheel's On Fire."

This time, when they hit the road, the Pumpkins will be showcasing a new sound. Adore, which clocks in at over 72 minutes in length, is a radical, wildly adventurous album. Corgan has set timeless melodies to music that, for the most part, sounds like it is the work of soulful aliens. With the exception of the acoustic guitar that opens the first track, "To Sheila," and the piano that dominates a few tracks, there is hardly a conventional sound on the album. Instead, drum machines, samples, treated drums, treated samples, synths and all manner of odd noises have been used to create an intensely intimate, powerfully revealing work.

Guitars, traditionally a mainstay of the group's old sound, are practically nonexistent. You'd perhaps expect guitarist Iha to have a problem with that. He doesn't. When I join the threesome in the lobby and ask about the sound of the Adore material, it is Iha who answers first, almost playfully.

"Well, kick out one drummer, take out the guitars," he says, looking over at me through a pair of plastic-framed glasses.

"Get another drummer," D'Arcy says. "Kick him out. Get another drummer."

"Add some keyboards," Iha says.

"Play some lame-ass tunes," laughs Corgan. "And that's it!"

The rehearsal studio is a hive of activity. Pumpkins crew members are fussing with electronic equipment, conversing on cell phones, eyeballing faxes that are coming in from the group's New York-based management office. "First it was just one keyboard," says the group's tour manager ("He's really much, much more than that," says the group's publicist, Gayle Fine. "He's Mr. Everything."), who goes by the name Gooch, as he takes a seat behind touring keyboardist Mike Garson's bank of synthesizers. "Now look at them all."

"I guess it had some babies," cracks another crew member.

But the keyboards pale in comparison to the guitars. I stop counting at 40 guitar cases. And that doesn't include the two sitting open on the floor, each containing a shiny Hamer brand guitar. Guitar racks are filled with all makes and models: lots of Fender Strats and a Gibson SG, an old Danelectro and a Gibson Les Paul Jr. Marshall amps seem to be everywhere. In the very center of the room is a music stand. It is from this spot that Corgan leads the band through their paces.

From all accounts, tour rehearsals having been going well. "Smooth," says Stephen Hodges, a percussionist who has worked with Tom Waits. Hodges seems excited to be hitting the road with the Pumpkins. "Smooth" is how he describes the sessions; "evolving" is his take on the live sound of the studio-crafted Adore material.

Hodges says Corgan quickly realized that the loops and samples that work so well on the album aren't exciting enough for live performance. "So there are three percussionists," Hodges says.

In addition to Hodges, drummer Kenny Aronoff (known for his work with John Cougar Mellencamp and John Fogerty) and Garson (who has worked with David Bowie and Trent Reznor), the Pumpkins have enlisted multi-instrumentalist Lisa Germano (a solo artist who once played fiddle in Mellencamp's band) and percussionist Dan Morris.

"I think of us as the flying wedge," Hodges says of the percussion trio. "Kenny is the point of the flying wedge."

Hodges, who is getting ready for the afternoon rehearsal as he chats, says that during the first few rehearsals, Corgan was not bashful about indicating what he liked and what he didn't like. The head Pumpkin was looking to capture some of the powerful mood and feel of Adore.

"He told us what worked," Hodges says. "So you find an area to work in that he likes, and then you work in that area, finding ways to bring things out in the songs.

"We've got everything from a Glockenspiel to congas," he adds, gesturing to his percussion set-up.

Taking the ethereal, late-night sound of Adore, which Corgan has accurately described as "arcane night music," to the stage should be quite a feat. But rather than try to re-create the exact sounds that are on the album, the touring ensemble will be going for the feel, finding ways to convey the emotional resonance of the material.

Love, loss and faith are themes that dominate the new album, returning in song after song. But they are articulated in a very personal way. "You make me real," Corgan sings in the beautiful album opener, "To Sheila." "You make me real/ Strong as I feel/ You make me real."

Later in that same song, he reveals: "Lately I just can't seem to believe/ Discard my friends to change the scenery/ It meant the world to hold a bruising faith/ But now it's just a matter of grace."

While many of the songs are slow and moody, the Pumpkins do up the tempo with the first single, "Ava Adore," which features Matt Walker's industrial drums and, at times, a wall of noise. Priceless lyric: "Lovely girl you're the murder in my world/ Dressing coffins for the souls I've left behind."

"Tear" features an exotic, Zeppelin-style orchestrated sound. "Tear me apart/ Tear me apart from you," Corgan cries out to -- whom? -- a departed lover, a dead lover? "Where is your heart?/ Where has your heart run to?"

In "Appels and Oranjes" (renamed once Corgan remembered there was an early Pink Floyd song called "Apples and Oranges"), Corgan raises the stakes further, asking what would one do if all the most fundamental things that we take for granted could no longer be taken for granted. "What if the sun refused to shine?/ What if the clouds refused to rain?... What if, what is isn't true/ What are you going to do?"

This is heavy, personal stuff. Clearly, Corgan, now at the beginning of his 30s, has grown up, and with Adore, he's delving into some of life's strongest mysteries.

This is a far cry from songs like "Jellybelly" ("We're nowhere, we're nowhere, we're nowhere to be.../ living makes me sick") on Mellon Collie. As Corgan says, "I'm not just speaking to a teen-age heart anymore."

With the album completed, the group is focused on making sure that the world knows about it. After a "rumored" club warm-up date (see related story in May 1 SonicNet Music News), they head off on a 17-date European tour that will find them playing such unconventional locations as the Botanical Gardens in Belgium, the recently opened Guggenheim Art Museum in Bilbao, Spain, and the Tivoli Gardens in Copenhagen, Denmark.

And what, exactly, has prompted the group to play such unusual venues?

"I just wanna have fun," D'Arcy says.

"Just fun," agrees Corgan. "We're trying to take the corporate, hyped-up overload thing out of it for a while so we can just play."

"When you tour Europe -- whenever your tour anywhere -- everyone goes to the same places," D'Arcy explains. "These are the places where a rock band plays ... You go to the same places ... It's not interesting. It's a grind; it's a drag. Maybe the first time you go over you're excited, but after that it's just the same, the same and more of the same. We've never been to a lot of these places before."

"We're just trying to change the context in which we play," Corgan adds. "That's the best way to put it."

"Play different kinds of venues," D'Arcy says. "Breathe some life into it."

"We've done the arena-rock thing, it's just time to do something different for a while," Corgan says. "It's a different album, so it just seems like, would you go out and do the same thing?"

The Pumpkins say they're indulging themselves with the European tour. "Absolutely," Corgan says.

" 'Cause we're sure not making any money," D'Arcy says. Then she laughs.