The Beach Boys were singing "Good Vibrations" last night when the delayed fireworks show started, and although the pyrotechnics drowned out the music for some in the Independence Day crowd, they provided a spectacular backdrop for such distinctively American tunes as "Fun, Fun, Fun" and "Surfin' U.S.A."

The California quintet didn't make it on stage until about 9:40 p.m., concluding six hours of free music on the Mall. But the group, revitalized by its first album in five years, sounded fresher and more spirited than it had on any previous visit to the Washington monument. Though the new songs like "California Calling" fell far short of their classic '60s tunes, the Beach Boys' voices once again rode the roller-coaster harmonies without slipping and the rhythm section was aggressively punchy.

The highlight was easily a gorgeous version of "Wouldn't It Be Nice" by a trim, beardless Brian Wilson, who sounded better than he has on stage in two decades. Even the well-worn surfing medley took on a new luster as the voices blended instinctively and built the momentum higher and higher with each hit.

A long list of guests joined the Beach Boys and their six-man backup band. Ex-Led Zeppelin guitarist Jimmy Page led the way on a hard-charging version of Little Richard's "Lucille." Christopher Cross joined the choir for an extended version of "Good Vibrations." New Edition filled out the harmonies on "Help Me Rhonda"; ex-Doobie Brother Keith Knudsen and Mr. T joined in on drums for Chuck Berry's "Rock and Roll Music." And Joan Jett joined the crowded stage for the swaying chorus of "Barbara Ann."

The concert at the Washington Monument got under way at 4 p.m., an hour earlier than scheduled. The ever-changing list of acts changed some more: promised acts like the Gap Band, Joe Ely, Charlie Daniels and Chris Christian didn't appear, and New Edition and Christopher Cross made unexpected appearances.

The show began with D.C. funk band Radiant followed by Southern Pacific, a new California band of alumni from the Doobie Brothers and Creedence Clearwater Revival, which finished with a rousing version of "Born on the Bayou."

One of the best sets was turned in by the one band with something to prove: England's Katrina & the Waves, a new quartet that backs up irrestible pop melodies with a hard-rock bottom and a new-wave edge. Their current hit, "Walking on Sunshine," written by lead guitarist Kimberley Rew, is a perfect summertime hit: simple fun with a sing-along melody that Katrina Leskanich cheerfully belted out in a bouncy dance beat that the Waves banged home.

The show was well balanced not only for rock, country and soul but for new and old acts as well. After a perfunctory set by mellow country-rockers the Bellamy Brothers, the hot bubble-gum hip-hop quintet New Edition danced onto the stage in shiny purple jackets and bow ties. Spinning and dipping through clockwork choreography, the five teen-agers squealed, crooned and rapped their way through the long list of hits they've racked up in less than two years. If they often sounded too much like Jackson 5 impersonators, their youthful freshness allowed them to get away with it -- for now.

The Four Tops, the only great Motown group of the '60s to survive into the '80s with its personnel and sound intact, followed. Levi Stubbs, sporting a graying, full beard, led the quartet through a long medley of hits, and their voices showed no loss to time. If they didn't have New Edition's moves, their voices had an emotional depth the youngsters couldn't touch.

The show was running pretty close to schedule when the Four Tops went off, but then there was a long lull. A pickup quintet of members from Southern Pacific and the Bellamy Brothers band filled in for the late arrivals with a set of self-indulgent jams based on old Allman Brothers tunes. This was followed by endless radio music and announcements.

When Joan Jett and the Blackhearts finally arrived, they delivered hard rock with a lean directness unmatched by anyone else in this genre. Dressed in a blue satin jacket with white stars over red-and-white striped tights, Jett turned the slam-bang-slam-bang four-beat of "I Love Rock 'n' Roll" into a crowd shout-along. Even better was "Do You Wanna Touch Me," which was delivered more as a taunt than as a tease.

With time running out, the Oak Ridge Boys were limited to "Elvira" and other up-tempo pop hits. Minutes after they departed, the Beach Boys came on with the unforgettable introduction to "California Girls."