Providence--a city named in the hope that a direct compliment to God might place Him under some sort of obligation to its inhabitants--provides Jean McGarry with the fertile ground of her comic and gritty, harsh and touching cycle of stories. Weaving in and out of Airs of Providence is a novella telling the story of April and Margery Flanaghan, two sisters trying to grow up in this neighborhood and doing only a so-so job of it. And it is a job, in a world not clearly made for anyone, but better suited to an older generation. Surrounded by nuns and priests, uncles and aunts, biddies and oddballs, April and Margery do their best to be normal. They practice their penmanship, babysit, go to a prom, and try to be up to date. But how even to look normal in a world where you are always running up against uncontrollable mood swings, mysterious infirmities, unexplained sorrows? Over a period of thirty-five years, they sniff out neighborhood scandals, get an ''earful'' of what the others are up to, and rest secure behind their sets of double curtains in the knowledge that everything human and frail is on the outside, everything blameless and perfect on the inside. If the Airs of Providence are sometimes rough, they are always funny. They may be sad too, but it is a dry-eyed melancholy that is no relation--or perhaps just a poor relation--to the air of ''Danny Boy.''