Image1976 was a transitional year for pop. Glam was in its death throes, morphing into stack-heeled bubblegum; "progressive" rock had climbed to ever-airier reaches of complexity; blues-rock was losing steam; punk was on the horizon. That was the year 801 made its lasting, uncategorizable contribution to the pantheon.

Less a band than a sort of floating side project, 801 was largely a platform for musical adventurer Brian Eno, who'd donned mascara and ostrich feathers as synthesizer player for U.K. art-rockers Roxy Music, and Roxy guitar wizard Phil Manzanera. Eno parted ways with the band after the release of their 1973 sophomore album, spending the next several years creating his own warped, playful pop on records like "Here Come the Warm Jets," "Before and After Science," "Another Green World" and "Taking Tiger Mountain by Strategy."

Though he subsequently took a lengthy hiatus from rock song forms to develop his "ambient" sound (which would have an explosive impact on the development of techno, chillout and other electronic subgenres) and eventually became one of the most sought-after producers in music (hello, U2), Eno wrote some remarkable tunes during the first half of the '70s. Littered with skronky guitars, weirdly filtered synths and cicada-like drum machines, the tracks were an appropriately offbeat foundation for the man's droll, absurdist narratives.

When he and Manzanera decided to play a few shows as 801 (the name came from a line in Eno's dream-inspired number "The True Wheel"), they recruited a superlative crew of musicians and culled a set list from Eno's cerebral ditties, Manzanera's ravishing, otherworldly instrumentals, and a couple of intriguing cover songs. One of their concerts became the 1976 album "801 Live," which quickly reached cult status with experimental-rock fans, prog devotees and proto-punks. The disc happened to be the finest distillation of the band's many charms, with a focus and intensity largely missing from their studio work.

What is "801 Live?" A subtle sidebar to the grandiose history of prog? A ballsy corrective to the wimpy rep of art-rock? A belated final chapter in the saga of psychedelia?
Much of the credit for this goes to the aforementioned crew: brilliant bassist Bill MacCormick, incendiary drummer Simon Phillips, resourceful keyboardist Francis Monkman and fleet-fingered slide guitarist Lloyd Watson. Virtuosic without undue flash, generous in their interplay and effortlessly fielding multiple styles, these musicians' musicians take Eno songs like "Baby's On Fire," "Miss Shapiro" and "Third Uncle" — not to mention potent Manzanera cocktails like the polyrhythmic Latin-space-funk workout "East of Asteroid" and the searchingly gorgeous "Diamond Head" — to new summits.

And on the lavish reissue set from Expression Records/MVD Audio (part of the surprisingly extensive 801 Series), fans of the vinyl version of "801 Live" will at last hear excised tracks like the eerily cinematic "The Fat Lady of Limbourg" (augmented with an unexpectedly muscular, riff-heavy coda) and the contemplative "Golden Hours" (which boasts a riveting Monkman clavinet solo that braids pure pop and chamber music).

801's two covers, the Beatles' "Tomorrow Never Knows" (rendered as "T.N.K.") and the Kinks' "You Really Got Me," provide a fascinating '70s gloss on '60s rock; the Fab Four track, in particular, is a highlight of the set, with the trippy vamp of the original augmented by MacCormick's grooving explorations.

The "801 Live Collector's Edition" includes a second disc, of the band at rehearsal, taken from tapes MacCormick discovered while rummaging for photos. Though not revelatory (and of inferior sound quality), the versions found therein certainly will intrigue the "Collector" types called out in the reissue title.

So: What is "801 Live?" A subtle sidebar to the grandiose history of prog? A ballsy corrective to the wimpy rep of art-rock? A belated final chapter in the saga of psychedelia? The baroque beginnings of the alternative/new-wave revolution? A fiery fusion of world-pop invention and electronic squall? It's all of the above, at times, but ultimately it endures as an enthralling artifact of great live music, played by artists too creatively restless to occupy a single niche.