The Unpredictable Fire Burns On

U2

“Zooropa”

Island

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After the daring, 1991 high-wire gamble of changing its sound from the spiritually tinged anthems associated with “The Joshua Tree” to the dark, introspective “Achtung Baby,” you’d think U2 would have given itself an easier assignment this time out.

Yet this new collection, which arrives in the stores on Tuesday, is--once again--a U2 album like no other.

Instead of a warm, comforting work to balance the icy, futuristic textures of “Achtung Baby,” the album--recorded in the spring during a break between the group’s American and European tours--finds U2 delivering a collection that will sound even more radical to mainstream ears.

The surprises range from guitarist the Edge singing the lead vocal on a track (“Numb”) whose anxious, impersonal tone is closer to industrial rock than anything we’ve previously heard from U2, to Johnny Cash singing lead on a U2 song (“The Wanderer”) that could easily pass for one of the veteran country star’s own gospel narratives:

I went out walking

Through streets paved with gold

Lifted some stones

Saw the skin and bones

Of a city without a soul

What’s remarkable in all this is that “Zooropa,” despite its differences from other U2 albums, captures faithfully the spirit of last year’s high-tech U.S. stadium tour.

Though the “Zoo TV” tour was built around the music of “Achtung Baby,” that album’s songs were used as musical starting points to explore questions of reality and illusion as well as values lost and seldom found.

By the end of the tour, the Irish quartet seemed to be playing altogether different songs as the dynamics of the shows shifted in strange but invigorating ways. “Zooropa” captures those new dynamics, probing even more aggressively into what the band sees as the far-ranging disillusionment of the modern age.

The album’s title track, which opens the album, addresses the issue of false political promises and media overkill with a trace of sarcasm and humor. In it, singer Bono advises, “Be all that you can be / Be a winner . . . / Eat to get slimmer.”

He also touches on the disillusionment in these mocking lines from “Some Days Are Better Than Others”:

Some days are dry, some days are leaky

Some days come clean, others days are sneaky

Some days take less, but most days take more

Some slip through your fingers and onto the floor

Bono calls the new collection a Polaroid photo that shows exactly where the band is musically these days, and the description makes sense. In some ways, this music captures the spirit of the “Zoo TV” concerts so well that it stands as the first tour album that doesn’t include any of the songs from the tour.

In contrast to the deliberateness with which most U2 albums are made, the group--along with producers Brian Eno and Flood--worked in a freer and more spontaneous manner. In some places, the band even updates the cold, experimental fibers of Eno’s late-’70s work with David Bowie.

Mostly, however, the music simply reflects a confident, pumped-up U2, a band whose four members have once more gone into the studio with nothing more in mind than to make music with enough purpose and passion to excite and satisfy them. There is no higher standard in contemporary rock.