ROBIN AND LINDA WILLIAMS, those "Prairie Home Companion" perennials, are hand-in-glove harmony singers. Their potent voices fit perfectly on "Close as We Can Get." His clear, virile tenor and her richly vibratoed alto more than live up to the album title; though they ably split lead vocals and share instrumental duties, the Williamses sound best riding above the melody in hard, honest harmony. " While they haven't abandoned the folk and blues roots of their earlier albums, "Close as We Can Get" finds them moving closer to old- fashioned country, the emotionally visceral kind suggested by Hank Williams and Jimmy Rodgers, whose "Train Whistle Blues" opens the album on a yodeling high. The album features two other train songs (the Williamses' own familial lament, "The Leaving Train," and the Delmore Brothers' sprightly "Pan American Boogie"), suggesting the conflict between the restless nature and the longing for home that marks the Southern working class.

There are several uptempo cuts here, but the two best songs are classic, medium-tempo country ballads. "Hillbilly Hell," one of five Williams originals, kicks off as a parody of the idea of Hillbilly Heaven, but turns into a no- nonsense cautionary fable about misused gifts. (It also sounds like it was written 30 years ago.) "Poor Red Georgia Dirt," a Gary Stewart song that was originally a hit for Stonewall Jackson, is another moving meditation on family and hearth, two areas never far from the Williamses' hearts.

ROBIN AND LINDA WILLIAMS -- "Close As We Can Get" (Flying Fish FF327); at the Barns of Wolf Trap this Saturday at 8 p.m.