But what do pencil-necks like us know about the real America? “Don’t think we ought to give college degrees to anyone who can’t run a table saw . . . or overhaul a truck engine out in the backyard,” says the hero of of Waller’s new novel, B_Border Music_b (256 pages. Warner. $17.95). Texas Jack Carmine is Waller’s idea of the genuine article: pickup, Merle Haggard tapes, the devil-may-careness that leads him to spirit exotic dancer Linda Lobo away to Texas from a Minnesota gin mill. Meanwhile, Jack’s Walter Mittyish uncle goes to New Orleans and dances wity a real live black woman. “Rhomer knew she would taste and smell of Africa and chains …” Don’t think they ought to give book deals to anyone who writes like that. Still a man’s gotta review what a man’s gotta review.