Borderlands -- especially the United States-Mexico borderland -- have long served as backgrounds for depicting social instability, according to Thomas Torrans. And borders -- or magic curtains -- have readily been fashioned into exotic backdrops for films, novels, ballads, and tales in which characters shift easily from one culture to another. The protagonists are equally at home in both societies, or, at worst, at home in neither.True border novels form a literature that deserves a category all its own. There is an uneven quality -- a coarseness sometimes mixed with polish, running the gamut of emotion from the tragic to the comic.One recent fictional attempt to exploit the border's historical aspects is Fandango by Ron McCoy (1984), while one of the older efforts is that of the early twentieth-century novelist Will Levington Comfort in Somewhere South in Sonora (1925). Border fiction is often just part of a larger whole and a number of books, whether fiction or nonfiction, seldom if ever cross the magical line between the two cultures. They remain, for the most part, fully centered in either Mexico or the United States, such as J. Frank Dobie's very Texan A Vaquero of the Brush Country or his personalized account of his equestrian travels in northern Mexico, first published as Tongues of the Monte and later as The Mexico I Like.Film epitomizes the escape across the magic curtain. The Getaway (based on the novel by Jim Thompson) is exemplary. Carol and Doc (Ali McGraw and Steve McQueen) not only manage the great escape with a satchel full of stolen money, they do it by fleeing to the border after a long brush with death. Filmmakers have carved movies out of other novels. B.Traven's The Treasure of the Sierra Madre and Glendon Swarthout's They Came to Cordura are compelling looks at the vast and hard country that the border stitches together.Fortunately, corridos -- the voice of the people -- are not dead. They exist far afield, from the ball