The Allman Brothers Band’s At Fillmore East was, of course, neither rock and roll’s first live album nor the genre’s first two-disc set, but it gave both formats a cachet neither had enjoyed prior to its release in 1971. A tour-de-force of southern-based blues rock, much of it improvisational, the album also forged a template from which future jam bands such as Widespread Panic and Gov’t Mule would draw. To this day, the set packs a thunderous wallop.

At the time the Allman Brothers Band performed the Fillmore East shows, staged on March 12 and March 13, 1971, the group had two studio albums under their belt. From the start, however, the band had relied on relentless touring to build a grassroots following. As group biographer Scott Freeman has noted, Duane Allman was itching to capture the power of the Allmans’s live set on record.

“The stage is really our natural element, and we haven’t got a lot of experience making records,” Duane said, following the release of the band’s previous album, Idlewild South. “We get kind of frustrated doing the records, so I think our next album will be a live recording to get some of that natural fire on it.”

While the Brothers were, of course, known for their improvisational skills, the Fillmore shows were in fact carefully planned. The group had already played the venue (an old vaudeville theater located on Manhattan’s 2nd Avenue) four times during the past year, and in each instance the audience had grown. By the time the group took the stage for the first of four shows – two on Friday night, and two on Saturday night – they had rehearsed rough arrangements of the set list. In producer Tom Dowd’s words, the group was “ready to take on the world.”

“They were at their absolute peak, [and] the playing just flowed,” Dowd later said. “When Duane and Dickey [Betts] played together, it was frightening. You’re talking about two people who had feather fingers.”

The proof, of course, was in the music, and performances were indeed sensational. Beginning with “Statesboro Blues,” the Blind Willie McTell song that first inspired Duane Allman to take up slide guitar, At Fillmore East kicks into overdrive and rarely lets up. Fresh from a star-making role as second guitarist on Derek and the Dominos’ Layla and Other Assorted Love Songs, Duane powers the song with stinging bottleneck runs that punctuate Greg Allman’s muscular, gospel-tinged baritone.

Performances of Elmore James’s “Done Somebody Wrong” and the fiery instrumental “Hot ’Lanta” occupy similar stylistic terrain, while the performance of Betts’s “In Memory of Elizabeth Reed” was hailed by Dowd as “the greatest fusion … I’ve ever heard.” Similarly, the 23-minute “Whipping Post” finds the band locked into the sort of cosmic interplay often associated with great jazz artists.

With 20 reels of tape from which to draw, Dowd turned mostly to the fourth show as he pasted together the dazzling performances. Because of a bomb threat, that particular show had been delayed in order that the venue could be searched. Seemingly energized by the interruption, the Allman Brothers delivered a marathon performance that didn’t conclude until sunrise.

In the aftermath of the shows, everyone associated sensed the group had something special on their hands. Remarkably, however, considerable effort was required to persuade executives at Atlantic Records, who were funding Capricorn Records, to release the album as a two-disc set. In a 2001 interview, Capricorn Records founder Phil Walden explained.

“We had been through numerous negotiations with Jerry Wexler at Atlantic to let us do a double album of all those long cuts,” he said. “Wexler wanted us to edit the release down to a single album, and he was adamant about that. He said we couldn’t afford to put out a double album by the Allman Brothers. He felt we wouldn’t be able to pay the publisher and so forth, because this was just a developing group.”

Walden continued: “Finally, he said we could do it if we made a deal with the publisher. So we did that, but then we hit him with our other news, which was that we wanted to sell this double album for $6.98. A single album was $6.98 in those days; $8.98 and $9.98 were the double album prices. But we insisted on this, because we were trying to suggest that the Allman Brothers Band was ‘the people’s band.’ We wanted the album to carry a price tag people could easily afford.”

In the end, of course, At Fillmore East not only connected with “the people,” it also spawned a host of similarly sprawling two-disc sets (Humble Pie’s Rockin’ the Fillmore being the most obvious example). More importantly, the set sparked a “southern rock” movement of epic proportions, paving the way for the likes of Lynyrd Skynyrd and The Marshall Tucker Band to gain a foothold with the public at large.

Tragically, Duane Allman lost his life just months after the set was released. Had the pioneering guitarist done nothing more than leave behind these performances, however, his legacy would have been assured.

“Both in its conception and in its execution, At Fillmore East remains one of the finest live albums ever made,” said Walden. “In my opinion, it's one of the foundation albums of modern music."