Despite having just completed a brief, wholly satisfactory down-tempo song-and-dance number followed by a brief pause that led many to believe he had completed all singing and dancing, tuxedoed entertainer Rick Werner, 29, made it clear Tuesday that he was just getting started. After being tossed a top hat and cane by an unidentified offstage associate, Werner performed high kicks in time to three brassy, ascending notes as a large curtain rose behind him to reveal approximately four dozen identically dressed performers. 'Hey, now that's the stuff,' Werner said as he stepped sideways across the stage making tight, circular motions with flat-palmed hands. 'Cha.' At press time, dazzled sources had not yet confirmed whether the stage was retracting to reveal a pool full of synchronized swimmers. 