Fernanda Eberstadt, an ambitious, resourceful novelist with a lush style and a Manhattan background, has written, in “Little Money Street: In Search of Gypsies and Their Music in the South of France” (Knopf; $24.95), a piquant nonfictional account of her successful attempt to penetrate the Gypsy enclave of Perpignan. This city, at the eastern end of the Pyrenees, holds five thousand Gypsies in an urban center of around a hundred thousand. Eberstadt and her husband, Alistair Bruton, and their two small children found themselves living in a rented house outside Perpignan because Bruton, we are told a bit abruptly, “was writing a book about the decline of religion in modern Europe, and was looking for somewhere half to hole up in, half to base it on.” Why this obscure, unprosperous, and atypical region of France—the province of Roussillon, ceded by Spain as late as 1659 and still regarded by many of its natives as “northern Catalonia”—should serve his investigative purpose is left mysterious, but its usefulness to his wife is made clear. In the course of a cosmopolitan life, she has always, she tells us, “been drawn to Gypsies”: after a childhood glimpse of a trio begging at an outdoor café in Paris, she has “sought out Gypsies—Gypsies who run travelling circuses in Ireland, or sleep in the ruined Byzantine city walls in Istanbul, or camp on the beach in Palermo, or even live in a brownstone basement on the Upper West Side of Manhattan.” Though her six years of living in Roussillon may have left her with “the same attraction to their intractable difference,” readers of her account, if this reviewer is an example, will be cured of any faint desire they may ever have entertained to live like a Gypsy.