An elegant coachman on a 19th-century coach pulled by two horses slowly trots through the streets of Rome--the Corso, Piazza del Popolo, the Imperial Forums. Inside the coach is an outstanding visitor: an ironic pot-bellied composer, the best of his century, who after two centuries returns to the three big Italian art cities--Naples, Rome, and Venice--where he lived and wrote his famous operas and "crescendo." He is Gioacchino Rossini. He goes in his coach through the contemporary streets and squares of Rome, through the alleys, along the promenade of Naples, and on his gondola through the canals of Venice, where he first directed and performed "The Bill of Marriage