Sometimes it can be the simplest gesture that tips off an audience they’re in for a theatrical treat. In the recent City Center Encores! revival of Where’s Charley? the clue took place in the opening quartet in which two young couples alternated in duet. When they weren’t singing, the performers pulled their chests up high, linked arms and bounced subtly and elegantly on their toes in time to the music. Here was imaginative choreography where an understated move (think Fosse’s hat-tilt) said everything! Here were singers who could dance! With just one exception, the entire performance lived up to its early promise of stylish fun.