The Sorrows of Frederick won much praise in its 1975 Off-Broadway production, and no wonder; Linney (whose early 1960s novels, Heathen Valley and Slowly By Thy Hand Unfurled, were quiet triumphs) is one dramatist who can handle grandscale themes and personalities, who can dish up dialogues between Frederick the Great and Voltaire that are neither stodgy nor campy, who can vitalize a sprawling, time-traveling portrait of Frederick II with wit, passion, and intellectual vigor. He seems a different playwright when he moves from Prussia (1712-1786) to the rural South (now), less special but no less skilled. ""You and your idjit son have stole my wife,"" says Coleman Stedman to Rev. Obediah Buckhorn, leader of the Pentecostal Church of God Snakeholders. And it takes a spirited service (stage direction: They hand her a huge rattlesnake) to deflect Coleman's fury. The dialogue here is as sharp-funny and tough as the Frederick dialogue is literate and evocative; Linney's versatility is only one of the virtues that make this pair of plays evidence of a distinctive, idiosyncratic talent.