It was a strange sight at first — a tall, slim, African American on the sidewalk at the intersection of 38th Street and College Avenue, arms outstretched, feet gliding, body twirling languidly. But after many years of this, the site ceased to be strange and instead was familiar, and even lovely. Motorists honked their approval, at which point the dancing man invariably faced the honk, bowed his head and threw a hand high into the air. It was more than a wave, more than a salute.