A WHITMAN SONATA - At the New Playwrights' Theater through October 29.

If the music weren't different, you would think the New Playwrights' Theatre was putting on "The Fantasticks." All those lovable hayseeds wander about, their eyes dazedly fixed behind and above the audience's heads to show they are thinking poetic thoughts, singing and narrating their way through a story about east-west-home-is-best, or maybe it's home-is-where-your-heart-is.

There was nothing much wrong with "The Fantasticks," and it's not the music that is the problem. Thom Wagner's score is varied and interesting. The problem is that they are calling it "A Whitman Sonata," claiming that the chief character is Walt Whitman, and then hanging him with his own words.

Walt Whitman is more or less fixed in the national imagination as the 19th century's white-haired duty old poet. The kind of healthy, upbeat, patriotic lustiness he had has been done often and much worse since, but his freshness in his time, and the strength with which he wrote, earned him a reputation that has endured.

In Paul Hildebrand Jr.'s script, Whitman, as played by Jim Brady, is young - okay, Whitman must have been a dirty young man before he was an old one - but a young creepy bore. He keeps fasterning onto people with an unnatural disregard for their obvious desire to get away, quite understandable in the cases of a wounded soldier trapped by Whitman's possessive nagging and a traveling companion who has trouble making Whitman understand that he doesn't want to be followed to the ends of the earth. Gardner Hathaway has an impossible problem with these two roles when he is expected to show a change to deep-rooted affection. It is incredible to think that the traveler who had managed to shake such a companion would then suggest that the two acquire joint property in Australia.

It has taken some skill to fashion Whitman's own words into the speeches of a whiney fuss-budget. He has been reduced to a dispenser of trite travel tips and conventional advice. Descriptions of Whitman's memorable presence in Civil War hospitals do not indicate that he was running around pestering people to write home and eat up all their chicken soup - er, rice pudding.

Then, in the direction, Hildebrand seems to have had an attack of poetry. There is no other way to account for the crazy, spotlight-in-the-eyes trance that the entire cast is in, whether a character is supposed to be a pregnant woman apparently congratulating her husband on deserting her or a black soldier apparently idealistically motivated to beat up the patients.

When last Walt Whitman heard America singing, that was not the tune.