TV REVIEWS : A Long Time Gone Indeed : Concert Shows a Crosby, Stills & Nash Content to Coast on Past Glories

“Crosby, Stills & Nash: The Acoustic Concert”-- being shown, with pledge breaks, tonight at 10:30 on KOCE, Channel 50--opens with the sound of cheering and the sight, in a still-photo montage, of the singers as princely young troubadours. At the time of those photos, circa 1969-70, CS&N; seemed the glamorous epitome of romance and social relevance in rock.

What follows, though, is a concert (taped last November at the Warfield Theater in San Francisco) at which an audience’s collective sense of nostalgia let the same threesome--now avuncular middle-aged troubadours--limp through a dull, creaky performance while reaping an outpouring of adulation all the same.

The problem with this 12-song concert segment is that Crosby, Stills & Nash simply doesn’t cut it as a harmony trio--at least, it didn’t that night. Admittedly, CS&N;’s complex harmony blend is a tricky, ambitious weave in which the voices must scale sudden steep cliffs and swirl between moods earthy and ethereal. There have been nights since Crosby’s 1987 comeback from jail and drug addiction when CS&N; pulled it off beautifully. This show points up the group’s maddening inconsistency.

The most glaring problem is Stills. In the group’s early days, he was the chief cog in CS&N--; its most significant songwriter and most gifted all-around musician. Here, he sounds sadly diminished as he tries to negotiate such trademark songs as “Suite: Judy Blue Eyes” and the Buffalo Springfield-era “For What It’s Worth.” Stills’ voice here is an erratic, hollow husk. It’s hard to build a gleaming harmony structure when your group’s lower-register foundation is so shaky.

Crosby and Nash both sound like reasonable approximations of their better selves, especially during “Taken at All,” an obscure pretty song culled from the CS&N; vaults. They sing it as a duo, creating a pleasant reverie while Stills confines himself to a rippling acoustic guitar accompaniment.

The group’s political material also lacks bite. Crosby’s “Long Time Gone” comes off shouty and shrill, and there is no attempt to connect it to present developments. The song seems inserted merely for the sake of pacing, as bluesy, rhythmic relief in a program dominated by ballads.

The same goes for “For What It’s Worth,” which is tossed off as an audience-participation number divorced from its Vietnam-era themes of paranoia and factional strife. The anti-war elegy “Daylight Again”/”Find the Cost of Freedom” is buried safely in the distant past, sung against a backdrop of photographic images from the Civil War.

These songs still could pack immediacy in the hands of singers intent on drawing connections between the past and the present. But Crosby, Stills & Nash have ceded that vigor and alertness to Neil Young, who keeps growing as an artist while his old pals only drift along.

They seem satisfied with drifting. The threesome punctuates most songs with an assortment of back-slapping, finger-pointing, hand-shaking and other self-congratulatory airs.

Given his stationary subjects, director Jim Yukich tries hard to generate visual interest by superimposing ghostly close-ups atop wider shots of the performers, and dissolving and reforming images to create a sense of movement and changing perspective.

This can be disorienting. The camera sometimes pulls back for extra-long shots from the cheap seats, taking us exactly where most concert-goers would rather not be. Sometimes we seem to be swirling through the theater, watching from the perspective of a trapped sparrow fluttering in the rafters, and no doubt wondering what all the fuss is about concerning those squawky songbirds on stage.