The Spell of a Soft Voice : WE ARE STILL MARRIED : Stories & Letters <i> by Garrison Keillor (Viking: $18.95; 328 pp.) </i>

Garrison Keillor, as you must know from those serpentine, rapt monologues he spun out weekly in front of his “Prairie Home Companion� radio microphone, is a born storyteller--you could almost hear his thoughts gather and carry like quickening weather. He isn’t confined to Lake Wobegon’s home-cooked anecdotes in “We Are Still Married,� however. America is the recipient of that soft, ruminant voice’s report, even when momentarily transported to Denmark or Greece.

The book is a compilation of stories, letters and some of the unsigned pieces he wrote for The New Yorker magazine’s “Talk of the Town� section. Few of them are directly autobiographical, but in almost all you can make out the tall figure of this (prematurely) “old and irritable man� shunting between indignation over the Reagan years--and the fathomless disappointment America has visited on the lives of its adults--and the continuous wonder and anticipation of setting out, whether from the anvil-hard flatland of Fundamentalist Anoka, Minn., or on a horrible subway ride to New York’s Woodlawn cemetery.

Most of his satire is tinder dry. “Who We Were and What We Meant by It� is a sendup of every arts movement in America in the last 30 years that self-destructed the moment the matchstick of reality touched the cloud of its flatulence, only to be enshrined in the memory of its True Believers--people who were never there in the first place. “The Current Crisis in Remorse� rivals his earlier gem, “Jack Smith, Arts Administrator,� for its handling of cynical social service bureaucracy, and not incidentally, a phenomenon quite in keeping with our current moral dislocation, where the first thing we want to do in the wake of something terrible is to forget about it, “put it behind us.�

“A Little Help� applies lethal paper cuts to the overblown sanctimoniousness of show-biz celebrities bent on Good Causes. “Meeting Famous People,� conversely, shows us a celebrity ignominiously and fatally victimized by fans and other parasites. “Lifestyle� describes a quick arc of Yuppie gentrification and collapse of a town called South Roxy, imploded in a paper economy, a boutique mentality.

That increasingly busy, trashy emptiness yawning under America like a continental toxic dump is something that draws Keillor’s concern and even anger (he calls television “that sleaze hole�). He’s equally fascinated with the benign image of Ronald Reagan that floats over the landscape like a happy face. Of Reagan, he writes: “He himself was a huge success, the most outrageously successful, high-flying Irish politician of his day, with a honey voice and a twinkle and a wave and a duck of the head, the most boyish seventy-five-year old man in America, hard to lay a glove on, as light as a kite. Nothing he said ever came back to haunt him. His mastery of the air baffled and dazed his enemies, who couldn’t take seriously a man who refused to face up to the facts of the American decline.�

But Keillor is not a polemicist. If you hear the gloom of mistrust in the voice of this shy man out of synch with the various hustles that surround him, the character that peers out from these composite pages has an enormous capacity for tolerance and wonder. Anoka was a place to flee from, but it gave him a religious gift. Few writers could get away with a passage titled “The Meaning of Life,� for example, without having you glance over at the liquor cabinet for a stiff reprieve from a good man’s tedious earnestness.

“Even in a time of elephantine vanity and greed,� he writes, “one never has to look far to see the campfires of gentle people. If we had no other purpose in life, it would be good enough to simply take care of them and goose them once in a while.� The vulgarity of “goosing� someone may be what saves this passage from sentimentality, but the segment as a whole is characteristic of Keillor’s faith in regeneration; that tone of sharp-eyed appreciation permeates the book. And his characters stay true to themselves. In “What Did We Do Wrong?� a tough tobacco-chewing young woman named Annie Szemanski becomes a huge success as a major league ballplayer, but won’t otherwise play to anyone’s expectations--either feminist or front office or fan--and packs it in, as intractable as Bartleby the Scrivener.

Early on Keillor writes: “My cash crop is humor, a bastard genre of literature that includes Mark Twain and the gentleman of the old firm of Benchley, Thurber, Perelman & White and also includes ‘How to Talk Suth’n,’ ‘Buddy’s Big Book of Booger Jokes’ and ‘Funny Fotos of Cats in Hats,’ a mixed field.�

Keillor is well-placed in the old firm. His prose is clear and adroit (though his poetry is tone-deaf), and his humor works in the tradition of corrective clear-sightedness. The underlying impulse of this book is the gathering of wisdom. Even in the title story, an allegory of a fairly ordinary married couple thrust into fame by a snoopy magazine reporter, the process of celebrity distorts their lives into hideous tabloid blowups and nearly wrecks their marriage.

Many of the characters in “We Are Still Married� click apart like billiard balls. But many more gather each other in. Willa returns to Earl in Minnesota from New York with the corpse of Biddy, their dog.

“My friends can’t believe I took her back after all those things she said about me, but I can’t see where it’s any of their business. I told her there was no need for her to apologize, so she hasn’t. She did scrap the movie project and the book, though. The substitute-host deal fell through when the regular host decided he wasn’t so tired after all. Except for our two dogs, Betty and Burt, we’re almost where we were last summer. The ice has melted on Lake Larson, the lilacs and chokecherries are in bloom, soon the goslings will hatch and their mothers will lead them down to water, and everything will be as if none of this ever happened.�