LIVE rock albums, especially the pompous two-record variety, generally are an excuse for extended guitar work and prolonged drum solos. A marketing strategy and a self-indulgent ploy for the lack of live performances needed to justify their release. Perhaps video discs soon will rectify this problem. In the meantime, we have to contend with live double-albums by the two exemplars of commercial Los Angeles rock -- the Eagles and Fleetwood Mac.

Only a storeroom dummy could sit through all four sides of "Eagles Live" (Asylum BB-705) without falling asleep. There are no twists to thier "live" interpretations: They're the same old songs merely given a faithful run-through. Moreover, the deck is clearly stacked in favor of hits from "Hotel California" and "The Long Run," the band's two biggest-selling albums.

The album does contain one curiosity, a nine-minute version of Joe Walsh's "Life's Been Good." The song's message offers a cynical jab at the fatcat status that the Eagles epitomize, and it's performed with that in mind -- precariously, sloppily, and with carefree abandon.

Sides 3 and 4 are soporifics, primarily composed of mellow mood music. Although two lovely harmony ballads, "Seven Bridges Road" and "Saturday Night," recall the early country-rock of Buffalo Springfield and the Byrds, their delicacies are undermined by brash delusions of grandeur. There's an attempt to kindle "All Night Long" with the flame of imitation rockabilly, but it misses its mark. And on their anthem, "Life in the Fast Lane," the Eagles travel down the highway on four flat tires. Finally, on "Take It Easy," the band moves with an optimistic enthusiasm they've rarely expressed, concluding the mammoth enterprise with some genuine rock 'n' roll. As an acknowledgment of this fact, the close-out groove is nothing but cheering pandemonium.

Fleetwood Mac is the band that defined catchy yet profound pop for the late '70s. Like the Eagles, they are the product and the producers of Los Angeles' studio-perfected, hedonistic rock. But unlike the easygoing Eagles, Fleetwood Mac has managed to work serious themes into their music, as evidenced by last year's complex and highly underrated "Tusk."

"Fleetwood Mac Live" (Warner Bros. 2WB 3500) was largely assembled from recorded performances made during the band's recent one-year "Tusk" tour throughout various exotic cities such as Paris, Tokyo and Passaic. The included songs are primarily from "Fleetwood Mac," "Rumors" and "Tusk," although there are a few surprises (for instance, a kinetic version of Peter Green's "Oh Well"). Even though each song was recorded at a different location, they flow into each other with such smooth continuity that the two-record set seems like a single inspired concert. "Sara," all seven minutes' worth, is an absolute joy -- never has this band sounded more like Buddy Holly's Crickets backing up Jackie DeShannon.

Nevertheless, most of the tunes from "Tusk" are too loose, like reflex actions, perhaps because at the time of these recordings that album was relatively new. For example, a nine-minute expansion of "Not That Funny" is much too long; Lindsey Buckingham's vocal tricks become awkward and silly, and the band's wandering jam is extremely embarrassing. The album's other major weak spot also happens to be a padded Buckingham song, "I'm So Afraid." Slowed down to a turtle's pace, the performance features the band posing as heavy-metal rompers while Buckingham does his best to croon like Cher.

But these are only trifling incidents in an otherwise bountiful assemblage of vitally alive music. Compared to the original, "Monday Morning" is like a wild bull in a china shop, and the album's epiphany, "Go Your Own Way," rocks with the strenght of the Clash or Bruce Springsteen.

Recorded before an intimate gathering of friends and crew at Santa Monica's Civic Auditorium, three new songs evoke some tough romanticism. Stevie Nicks' "Fireflies" and Christine McVie's "One More Night" offer absorbing make-out music for the mind. Even more breathtaking in its simplicity is the band's interpretation of Brian Wilson's "The Farmer's Daughter," a quick tease and a nod toward the sun-and-surf sensibility that the Beach Boys undeniably invented.