For the 20th anniversary of their landmark Achtung Baby LP, U2 have chosen to release approximately 273 (I may be exaggerating here) different versions of the inevitable reissue set; the Super Deluxe Edition boasts six discs of music and four DVDs, and that’s not even the most extensive set available. It begs the question: why Achtung Baby? After all, prior to the album’s 1991 release date, U2 had a bona fide discography to their name, and titles like The Unforgettable Fire and especially The Joshua Tree were immensely well-received. And yet, those two albums were released in Super Deluxe editions that were packaged, like most standard reissues, with simply an extra disc of material and a bonus DVD. Why, then, is Achtung Baby‘s reissue approximately the size of a Volkswagen?

There are several ways to answer that question. The most obvious, and cynical, response is that U2 are trying to milk superfans for all they’re worth, which may have a certain level of validity, but it seems a little pessimistic. There’s also the fact that Achtung Baby, drawing inspiration as it did from Bowie’s dance-influenced Berlin-era records, lent itself to remixing a lot easier than anything else the band had released prior, thus necessitating a daunting two discs’ worth of remixes. But if it’s all the same to you, let’s collectively agree to assume that the reason the reissues of Achtung Baby are so exhaustive is because, quite simply, it’s U2’s best album.

That doesn’t change the fact that Achtung‘s Super Deluxe edition is positively exhausting to listen to. Those two discs of remixes are an endurance test – even if the idea of stretching these songs into 8-minute rave parties appeals to you, mixes of “Mysterious Ways” and “Even Better Than the Real Thing” monopolize the lions’ share of time dedicated to remixes, to the point that a front-to-back listen to the entire set severely wears out the welcome of two of the best pop songs on the record. (For the record, the Perfecto Mix of “Real Thing” fares best, soaring gospel vocals driving home the “take me higher” outro, and the way the Tabla Motown Remix of “Mysterious Ways” transforms the shimmying grooves of the original into a slinky, percussive Peter Gabriel b-side is pretty fascinating, but they all bleed together eventually.)

Fortunately, the other bonus discs do what bonus discs are supposed to do – they peel back the layers to provide an engrossing glimpse at the process of crafting the perfect final product. A disc-length collection of b-sides and remixes intrigues by unveiling a labyrinthine series of corridors that the band could have taken – “Alex Descends Into Hell For A Bottle of Milk” hints at a collision between the growling low-end of “The Fly” and the chiming, expansive riffing of “Until the End of the World”. The fascinating “Lady With the Spinning Head” comes the closest to sounding like it would have fit on the album proper; somehow, that’s not due to the fact that “Zoo Station”, “The Fly”, and “Ultraviolet” all spun off from this track, although it’s pretty mind-blowing to listen to it and pinpoint each musical cue that, eventually, splintered off into the foundation of a fully-formed song. (Over on one of the remix discs, an Extended Dance Mix of “Lady” draws these lines explicitly by pairing the track with the sinister “Fly” riff, and the genesis of the chord progression is fairly obvious.) “Salome”, all bass groove and blues guitar and canned handclaps hints at the Americana direction Rattle And Hum hinted at, but oddly-placed electronic effects make it just weird enough to work; “Oh Berlin” and its spoken-word verses takes the form of a wintry hymn of reverence, laying bare the titular city’s influence on the recording of Achtung Baby. The disc is also dotted with covers, but only a surprisingly warm take on Lou Reed’s “Satellite of Love” really fares well, hinging as it does on the Bono’s supple falsetto during the chorus; unexciting renditions of “Paint It Black” and “Fortunate Son” prove obtuse and plodding.

Sure, a lot of this sounds like old hat for U2 diehards – after all, superfans typically seek out things like b-sides and rare material. The real treat here is the inclusion of Kindergarten, a disc that showcases, sequentially, the original versions of Achtung Baby‘s twelve perfect songs, and it’s utterly fascinating; those intimately familiar with the record will delight in hearing drastically different lyrics, listening to extra verses that were eventually repurposed into bridges and pre-choruses, and in some cases, fairly dramatic tonal shifts from embryonic form to final product. We get to see “Tryin’ to Throw Your Arms Around the World” in its original incarnation as a ramshackle campfire singalong (this particular version’s rough enough that Bono audibly flubs a line by chuckling his way through it); “Who’s Gonna Ride Your Wild Horses” doesn’t sound nearly as polished as it does on the record, but Bono contributes a particularly raw and wrenching vocal; “Mysterious Ways” retains the Madchester rhythms of the final product, but replaces the melodic pre-chorus with a tense spoken-word build-up, each detailing a list of fears before the background singers chime in with “it’s all right, it’s all right, it’s all right”. Most of the powerful “Ultraviolet (Light My Way)” sounds intact – no major lyrical changes or shifts in mood here – but Bono’s ethereal, pained intro (“sometimes I feel like I don’t know…”) is found after the third chorus and before the coda. It’s all very cool, particularly for those of us who’ve connected to these songs in their released versions.

With all of these goodies, it’s easy to forget that, first and foremost, this is an album reissue, and not a compendium of compelling curiosities. Achtung Baby proper may not sound a lot different in 2011 than it did in 1991, and really, that’s a good thing; remastering is an excellent concept, but it’s an album that’s so immaculately recorded that it really doesn’t require it. Still, the volume has been audibly punched up, so rejoice, folks who’ve had to crank their stereos dramatically to hear the album at the appropriate decibel level. More important than clinical engineering concerns, though, Achtung Baby is simply a great record – often lovelorn and anguished, often insidiously catchy and eminently danceable, often just as earnest as previous releases but less overblown. It’s moment after magical musical moment; “One” is still a piercing, potent ballad, “The Fly” still an incredibly cool juxtaposition of contrasting styles with a muscular, bat-out-of-hell riff and an impossibly gorgeous chorus, “Ultraviolet” still a quaking, heart-stopping vision of love and loss. The songs are perfect – over the course of 20 years, they haven’t lost an ounce of power. It still radiates romance and fidelity, and contrasts those ideals with unspeakably painful expressions of darker themes like domestic discord, romantic disillusionment, and obsessive yearning, all while remaining the most musically innovative and densely layered record of U2’s career. (Props due to Adam Clayton and Larry Mullen for their propulsive, dynamic rhythms; further props due to The Edge for making the guitar his own personal playground, perfecting the meeting point between technique and invention, beauty and chaos, long before we all knew that Tom Morello’s guitar always sounded super-cool.)

The Super Deluxe Edition of Achtung Baby isn’t always essential listening; the endless parade of remixes is tiresome, the b-sides and bonus tracks hit or miss, and the inclusion of follow-up record Zooropa smacks a little too much of either commerce or trying too hard to get us to relisten to Zooropa. But it’s never anything short of fascinating – and when you’re dealing with a record this compelling, unraveling threads and peering into unopened doors becomes part of the fun. With their extensive, exhausting series of reissues, U2 have provided a thrilling glimpse into the craft involved in making a classic album, and given those of us who have already devoted countless hours of analysis to Achtung Baby an opportunity to do it all over again.

Grade: A