In 18 very short poems, Hopkins returns to one of his favorite subjects, adopting a child’s voice (or once a mother pigeon’s) to express deep affection for city life, sights, buildings, noises, subways, entertainments and seasons. Reminiscent of Marc Simont’s art but with a more sinuous, energetic line, Hall’s watercolor urban scenes capture the big city’s scale while depicting both its bustle and its quieter corners. Tucking in identifiable landmarks or the occasional non-Roman sign, he takes a backpack-toting canine tourist and a small blue bird from San Francisco to Cairo, New Orleans to London, and leaves them at last on a building top, gazing sleepily out onto a generic moonlit skyline. Though ten of the selections were previously published in some form, their overall simplicity lends each an enduring freshness: “Sing a song of cities. / If you do, / Cities will sing back / to you.” Endpaper maps identify the cities depicted, though a key to assist untraveled children in the game is absent. (Picture book/poetry. 7-10)