Balletomanes daydream in vain about how dancers moved before film began to capture dance, but tap fans don't have to waste energy on such futile pursuits -- the hoofers of 40 years ago are still dancing. Jimmy Slyde, whose performance last night at Blues Alley drew an overflow crowd, may have gray hair and grab his back like a Harlequin feigning lumbago, but surely it's all a ruse, for Slyde dances with an energy and finesse undiminished by time.

His feet are his motor, propelling his body relentlessly; his arms dangle gracefully, dependent on the ever-present movement of those feet. They produce a soft flutter of sound as he slides and skips or turns in endless pirouettes. It must have been trying for him to dance to coldly programmed tape cassettes instead of a conspiratorial band leader, but he adjusted nobly. Once, as he danced only to the music of his taps, the audience spontaneously began to hum the missing song, taking its cue from Slyde's rhythm. He loved to dance almost as much as the audience loved watching him.

The high-strung energy of Carol "Sweet Feet" Vaughn, who, along with several friends, preceded Slyde on the program, was in marked contrast to Slyde's smooth, gentle looseness. Vaughn is an engagingly kooky and ebullient performer and draws her inspiration from such varied sources as channel swimmmers and anthropological findings. She has an expansive style -- arms wave wildly -- and her routines range from the teasing and sultry to the generously effervescent. Vaughn is almost as good a comedienne as she is a dancer -- the dedications for each number were apt and genuinely funny.