AT the Guthrie this season "Death of a Salesman" expands with new life, Pierre Corneille's 17th-century French comedy "The Illusion" leaps the centuries, and even that old chestnut "The Man Who Came to Dinner" by George S. Kaufman and Moss Hart sparkles around the edges.In the skilled hands of visiting director Sheldon Epps, the rust of decades of tired "Salesman" productions has been polished away. With excellent African-American actors playing the central characters at the Guthrie, the Loman family's struggle takes on futher meaning without sacrificing the play's integrity. In Epps's production, Isabell Monk's outstanding performance as Linda Loman focuses the moral center of the play. Instead of the wimpy, distracted, fearful fool she is so often taken to be, Ms. Monk's Linda projects strength, nurturing, perception, and even religious fortitude. As Monk plays Linda, it is her love for her husband and children that places Willy's tragedy in high relief. Linda's flaw is that she has bought Willy's materialistic values. Because Monk plays her part with strength - even perhap s banking on the public's perception about strong black motherhood - Linda's failure is seen to feed the tragedy. Protective lies have no power to save. Out of affection and confusion she fails to make the right choices, too. Mel Winkler gives Willy a pathos and dignity he seldom expresses in other productions. That he is black makes Willy's wholesale purchase of the American dream of material success even more poignant. "Death of a Salesman" has never been on my list of favorite plays. I've always felt it fails to shed genuine light on Willy's situation. It describes the problem well enough, but its pallid determinism has always felt artificial and ineffectual to me. Willy, after all, refuses to see the truth, yet as one character says, "No one dast blame this man...." While this production did not erase my objections, it underscored the need for compassion, it brought out ideas in richer tones, and it moved me deeply. The Guthrie's artistic director, Garland Wright, has directed Corneille's galloping fantasy "The Illusion" with ingenuity and grace. An imagist of the first order, Wright's tantalizing compositions on stage serve the text well. "Illusion" is a play within a play within a play - an homage to the art of acting and the larger truths that may be rooted in theatrical illusions. As frothy as the play sometimes gets, and as broadly farcical as this production is, what undergirds "The Illusion" are the larger issues: forgiveness, creative response to harsh circumstance, and remorse that leads to change and thus redemption. It doesn't work every minute. The goofiness is occasionally dull. But its brilliance and power are undeniable. The weakest offering of the season is "The Man Who Came to Dinner" directed by Laird Williamson. The production is sound enough. But one can't help but wonder why such a dated piece was included. The story takes place in 1939 and concerns Sheridan Whiteside, an acerbic radio personality, critic, and columnist who finds himself laid up in the home of a middle-class couple he openly despises. Tyrannical and self-absorbed, Sheri dictates to everyone around him, and much of the comedy revolves around his bullying. Richard S. Iglewski's hilarious Whiteside doesn't bother to bluster, he snaps, insinuates like a snake, and charms like a school boy. The second best thing about the production is Brenda We hle as Whiteside's secretary. She makes Maggie a tough lady with a strong mind of her own and the wit to see through Whiteside. The production I saw was sold out. Audiences loved it. Maybe that's enough reason to have included it in the season.