The 25,000 fans who jammed the infield at Laurel Raceway Saturday night for the much-vaunted reunion of Paul Simon and Art Garfunkel cheered heartily when they heard the "The Boxer's" final, reassuring line: "After changes upon changes, we are more or less the same."

But it simply wasn't true--no matter how much the crowd wanted it to be. Simon and Garfunkel, like their original fans, may be older and wiser, but the passage of time has dulled their always questionable performance skills. And Saturday, too many of those old words came back at the fans in shades of mediocrity.

In the end, not even the warmest and most sincere surge of nostalgia could excuse such a performance, cloaked as it was in fervent memories of innocent days and once-brilliant songs.

Always the odd couple, they are a meat-and-potatoes act. Simon, the superb songwriter, is the meat of the matter; Garfunkel, the harmony singer and ballad specialist, is the fluffy potatoes. The band provided the richness and subtlety of a studio environment--appropriate gravy. But the meal itself was less fulfilling in execution than in anticipation, mostly warmed-over leftovers.

After a 45-minute delay because of traffic tie-ups, the concert kicked off promisingly with the uptempo "Cecilia." The audience, restless but good-natured in the cool night air, provided exuberant harmonies that never developed on stage. "Cecilia" segued into a hurried and uncomfortably ragged "Mrs. Robinson," and though the sense of hurriedness disappeared soon enough, the raggedness never did.

The show balanced Simon's rhythmically jubilant latter-day excursions--"Me and Julio Down by the Schoolyard," "Late in the Evening," "Kodachrome" and "50 Ways to Leave Your Lover"--with the duo's pensive early material--"Homeward Bound," "The Sounds of Silence," "America," "El Condor Pasa" and "Scarborough Fair/Canticle." Four new and unreleased songs pointed out that Simon's songwriting, as good as it can be, also lacks consistency. "The Late, Great Johnny Ace" is a poignant tribute to fallen heroes and lost innocence, while "Allergies" is a percussively compelling slice of verbal humor. But "Think Too Much" and "Song About the Moon" are slight and uninviting, not far removed from his lit-crit origins.

Among the best realizations of the night were the sinuous "Slip Slidin' Away," the brooding "Still Crazy After All These Years" and Garfunkel's rough-hewn but emotional rendition of "Bridge Over Troubled Waters," which remains an inspiring anthem to brotherhood and charity.

The essential miscalculation of the concert--and of this, the duo's first American tour since 1970--had to do with what people remember Simon and Garfunkel for: the gentle intimacy and soft-spun immediacy of songs that spoke directly to a great part of the generation that came of age in the '60s. On Saturday, there were state-of-the-art audio-visuals, a tremendously inventive stage set, a 100,000-watt sound system, a precision 11-piece band and a 700-square-foot video screen for the huddled masses yearning just to see. The concert was anything but intimate.

Simon and Garfunkel present a most ineffective stadium-style act, because neither projects much character in support of Simon's impressive lyrics. Neither singer is particularly compelling, either: Simon's soft baritone is thin, quavery and lacking in bottom, while Garfunkel's choirboy tenor is quivery and tends to flatness.

Worse, the ethereal harmonies that once elevated so many of Simon's songs to anthemic status were sloppy and out of kilter for much of the two-hour concert. The singers don't seem to like each other--they hardly exchanged glances during the program, instead singing without speaking--but they owed it to the public to rehearse that end of things as much as they obviously rehearsed the band.

Perhaps there was no way the night's performance could live up to the line from "Johnny Ace," which recalls a time when "the music was flowing, amazing and glowing."

By the time Simon and Garfunkel drifted into the sweet melancholy and pathos of "Old Friends," there was precious little passion. And there was more than a little irony in the splendid stage set, a painted mock-up of a classy '50s drive-in theater. In their heyday, Simon and Garfunkel suggested shared dreams and experiences, a serial that never ended except in stages of growth. This time around, it was painfully obvious that they were just passing through on a one-night stand.