Double revision

Mention the double live album and a host of '70s-era images flash to mind, none very pleasant: prog-rock bands with 20-minute drum solos, side-length instrumentals, ''Frampton Comes Alive." Following such indiscretions, the double live album became a symbol of the era's overindulgence, the untrammeled will to absurdity that represented pre-punk rock music's fatal bloat.

After a very long hiatus, though, the spirit of the double live album has made a resurgence, appearing in a variety of new guises.

Wilco, Slipknot, Green Day, and the Dave Matthews Band are just some of the groups to drop double live albums in recent months. In some instances, the traditional double CD has been replaced by a CD/DVD hybrid -- one live audio disc and one DVD of concert footage -- while others embrace the double-live form as a means of capturing an onstage concert experience.

As with most musical phenomena, the double live album has reappeared for reasons part artistic and part commercial, a joint function of accounting and aesthetics. After yet another year of lackluster sales, and with music downloading taking a major bite out of profits, record labels are more than happy to provide double the music (at a cost of pennies to produce an additional CD) in order to charge an extra $5 or $10 per album. Likewise, labels are hoping that the allure of bundled concert DVDs or other extras will convince fans to keep away from pirated albums or illegal downloading sites and return to paying full price in the stores.

''Ultimately, the cost of putting out a double album as opposed to a single is negligible," says Caryn Ganz, an editor at Spin magazine. ''But it provides fans with a sense that they're getting something truly special, and it allows artists to feel like their label is really supporting them."

''Any live record is going to be a document for the band's most hard-core fans," says Bob Johnsen, head of marketing at Roadrunner Records, which recently released Slipknot's double disc ''9.0: Live."

The tendency to supersize is a longstanding one, with fans seeing overstuffed releases as a sign of artistic inspiration and artists enjoying the opportunity to spread themselves over 2 1/2 hours of music.

''We all felt it was important to present a full picture of a Wilco concert," says David Bither, senior vice president of Nonesuch, the label responsible for Wilco's live ''Kicking Television: Live in Chicago." ''Part of what makes this version of Wilco so great is the freewheeling interplay of the band . . . which means that the songs will often not be concise miniatures."

For years, every major hip-hop star felt the need to release a double album. Some, like 2Pac's ''All Eyez on Me" (1996), the Wu-Tang Clan's ''Wu-Tang Forever" (1997), and the Notorious B.I.G.'s ''Life After Death," were critical and commercial successes. Others (Jay-Z's ''The Blueprint 2: The Gift and the Curse" in 2002) felt overinflated, industry greed run amok.

More recently, with labels realizing profits can be increased by releasing two related albums back to back rather than jointly, performers such as Shakira and System of a Down have put out what are essentially double albums in two halves. Shakira last year put out ''Fijacion Oral, Vol. 1" and ''Oral Fixation, Vol. 2," while System of a Down released ''Mezmerize" last spring and ''Hypnotize" in the fall. Why pay for something once when you can shell out $16.98 twice?

The recent reemergence of the supersized live album springs from two sources at opposite ends of the rock spectrum. Jam rockers such as Phish and the Dave Matthews Band made their reputations with epic-length shows, and devoted fans clamored for similarly comprehensive live albums. Even after its dissolution, Phish has put out a steady stream of live releases, including the ''Live Phish" series of triple CDs, and now the three-disc ''Live at Madison Square Garden New Year's Eve 1995," released just before Christmas. Similarly, the Dave Matthews Band's ''Weekend on the Rocks," the fifth live release from the Virginia frat-boy heroes, features a double CD augmented by an additional DVD recording of the performance. It came out in November.

The bigger influence, though, on bands such as Wilco and the Mars Volta in expanding their live-album pretensions is undoubtedly Pearl Jam, which took completism to entirely new levels with the release of more than 100 ''official bootlegs" of live shows from its 2000 and 2003 world tours. The plain-paper packaging may have been intended to emphasize the band's just-folks professionalism, but the overload of live recordings, most two and some three discs long, indicated a band that believed every drum fill and jot of feedback worthy of consumption.

With so much music in one package, the new spate of double live albums is intended to cater primarily to rabid fans. Those of us less than passionate about Iowan metalheads Slipknot will probably find the experience of listening to both discs of ''9.0: Live" roughly comparable to being hit in the head repeatedly with a two-by-four -- two hours of sludgy, indistinguishable songs, punctuated by profane outbursts about how the idiot media (thanks, guys!) has ignored and abused them.

''It's a complete immersion in the band," says Johnsen. ''Marketing-wise, we insisted the record be priced at $18.98, which is basically the price that labels charge for a single disc, so the added value makes it easier to sell. Two hours of music for the price of one." Twenty-four pages of photos of the band, each member lovingly outfitted to resemble his favorite imaginary serial killer, and a four-minute track titled ''Drum Solo" will do little to sway non-obsessives, but for those lucky few, everything is here except for the severed limbs in the freezer.

In fact, ''double live" has taken on entirely new meaning with the rise of CD/DVD live combinations, comprising one disc of audio and one of video (or sometimes both fused onto one disc). Coldplay, Maroon 5, Shakira, and Nickelback are just some of the performers who've released CD/DVD double live albums, their live albums joined by bonus DVDs of live material. Their efforts have recently been joined by Green Day's ''Bullet in a Bible," released in November.

Green Day's effort pairs a recording of a raucous, superb London performance with DVD footage of the show. It remains clear, though, which is product and which is filler: The concert DVD has band interviews interspersed with the live footage, meaning you can't play the DVD and watch the concert straight through. The double live CD/DVD is a terrific idea, but in this marriage of partners, there are no doubts about who's running the show.

The best of the new double live bunch is undoubtedly Wilco, whose deep catalog, varied musical palette, and audience-friendly demeanor make the band ideal for spreading out over the two discs of ''Kicking Television: Live in Chicago." A whispered, shivery ''At Least That's What You Said" sits next to the raucous audience singalong ''Theologians" and the guitar heroics of ''Hell Is Chrome." Lead singer Jeff Tweedy and his bandmates sound like they're enjoying themselves onstage, bantering with the audience and playing loose, tuneful versions of songs from their six albums.

Mixing up its attack, Wilco avoids the deadening sameness that plagues so many live behemoths. Sure to please fans and label bosses alike, ''Kicking Television: Live in Chicago" is the one unabashed triumph of the double live album's rebirth.

''We assumed from the beginning that it would most likely be a double record," Bither says. ''The music demanded it."

With the double live album evolving into a hybridized future set to include both CDs and DVDs, it is fitting that Wilco, itself a hybrid group (part country and part alternative, part avant-garde and part commercial) should step up as the format's flag bearer. The double live album, at its best simultaneously grandiose and intimate, demands such variety, and wherever the format heads in the future, it will retain the interest of fans and critics only by following the template laid out by Wilco. Anything less would be singularly unworthy.

WHAT'S YOUR FAVORITE DOUBLE ALBUM?
Share your memories and opinions on our music message board at www.boston.com/ae.