Hurry up and wait and wait and wait. That was the prevailing theme at the 11th Annual Budweiser Superfest at RFK Stadium Saturday night. While most of the acts scurried on and off stage, the crowd had to endure one long delay after another.

In fact, so super-sluggish was the pacing of the six-hour marathon that by 10:30 p.m., 3 1/2 hours after the scheduled start of the show, the unusually patient audience had heard only two 30-minute sets by Toni! Tony! Tone! and Bell Biv DeVoe. No explanations for the delays were offered and no apologies were made. All that punctuated the hours of recorded music heard throughout the evening was an announcement that Mayor Marion Barry was in the audience, which generated a rousing ovation, and a voice asking over the P.A. system, "D.C.! Are You Ready?" Ready? By the time headliner Luther Vandross made his post-midnight appearance, under then rainy, lightning-scorched skies, the crowd was nearly ready for the Redskins to resume play.

Vandross, having lost a great deal of weight in the last year, looked every bit as good as he sounded, though there was no hiding the fact that he was concerned with the weather. So much so, in fact, that when lightning flashed near the end of his classic romantic ballad "Here and Now," he echoed the crowd's sentiments by declaring, "It scares me too." And apparently it did, for moments later the singer abruptly capped his brief and unexceptional set. Stephanie Mills, who had been scheduled to precede Vandross but was moved so the headliner wouldn't be rained out, followed with a token 10-minute performance before dashing off as the rain increased and the audience dwindled.

Earlier, however, Oakland's Toni! Tony! Tone! and the New Edition spinoff Bell Biv DeVoe displayed great hip-hop energy and promise. Both groups set the crowd into delirious motion with a series of vigorously and imaginatively choreographed dance tracks, from the former band's kinetic version of "The Blues" to the latter's current smash "Poison." The tireless and long underrated Frankie Beverly and Maze, the one band that played a full hour, was also impressive, especially when the funk group reprised its early hits and enlisted the crowd's voices on its Nelson Mandela-inspired encore.