Any show on the spring trek by The Dead [ tickets ] will invariably bring up the dreaded question, "What would Jerry have done?" Saturday night at the 16,000-seat Forum, four original members of The Grateful Dead raised the specter of another deceased bandmate, Pigpen.

Organist Ron "Pigpen" McKernan died in 1973, eight years after forming the band that would morph into The Grateful Dead. Wittingly or not, the Forum set was heavy on blues and psychedelia, jams and material from the 1960s as crucially shaped by McKernan as it was by the more revered Jerry Garcia.

The entire 65-minute first set, which opened with a 45-minute jam centered on "Viola Lee Blues" and included "Bertha" and "Caution," consisted of songs from McKernan's tenure; only three of the 10 songs in the second half followed his death. Rootsy and druggy, the members of The Dead were focused and emphatic, singing well and keeping the meandering noodling to a minimum.

The L.A. crowd was largely a 45-to-55 demographic, the sort of crowd that grew up mythologizing songs that had been dropped from the set list a decade before they could make it to their first show. Many of those songs--"Dark Star," "Cream Puff War," "Alligator"--are receiving stronger, more focused performances now than when they were resuscitated in the 1980s and ‘90s.

"Dark Star," the mythologized classic just as famous for not being played as for its legendary versions, made it into Saturday's show, as did "Wharf Rat" and The Rolling Stones‘ "(I Can't Get No) Satisfaction," a tune that the band played when it was a hit and again between 1980 and '85.

Bob Weir, who stands center stage and by default plays the leader, maintained the focus on songs the way he has done with his band RatDog for years. During the nearly three hours of music-making, nothing was truly surprising or out of place. The musicians ventured to places listeners expected them to go; the more invigorating the solo, the louder the cheers grew.

Age of material did not slow the band in its attempt to re-create a Dead experience. The first set's extended jams included sections that veered deep into The Dead's jazziest phase, the mid-‘70s; "Shakedown Street" was stripped of its disco beat, slowed down and played out more soulfully than on record; the "space" portion that follows the drum solos was more uninspired than usual, with Weir and Warren Haynes filling the air with clinking and clanging sounds that went nowhere. (Once bassist Phil Lesh and pianist Jeff Chimenti entered, the improvisation began to coalesce).

Previous post-Garcia efforts that relied on the Grateful Dead repertoire--The Other Ones, Phil Lesh & Friends, RatDog--opted to replace Garcia with a like-minded guitarist, one that would play in the open-ended Garcia style that melds the circular motion of jazz with the linear discourse of bluegrass

Haynes, who shares lead duties in The Allman Brothers Band with Derek Trucks, is not that type of guitarist.

Rooted in blues, Haynes sticks to short, emphatic runs. He is a cut-to-the-chase type player; the only punctuation he uses is an exclamation point. Even in this blues-rich setting, his ideas sounded constricted when compared with the originals.

Beyond that, there was a feeling that he has not quite shaken off his full-time employers. Wasn't that a snippet of "Rambling Man" in "Bertha," a touch of "Blue Sky" in "Black Peter," a reference to "High Falls" in "Fire on the Mountain"?

It's a lose-lose proposition trying to replace Garcia. Sound too similar and the act becomes a cover band; stray too far form the source and it appears the guitarist doesn't get it. Haynes is straddling that fence, but his presence makes possible an evening celebrating the Pigpen era. And while The Dead has had more keyboardists than Spinal Tap has had drummers, Pigpen has never truly been replaced.