Walking Huck this morning in Studio City I hear a high pitched. . . I don't know what . . . over my shoulder. I glance over my shoulder and see a fat lady wobbling down Dilling Street on a tiny 22-inch wheel kids bike. Behind her: three other bicyclists. Lead lady is singing opera, weaving in and out of harmonies with her soprano girlfriend, who's taking up the rear. They're carrying on like chirpy birds in a Disney cartoon from the forties.