The Spirit of the Midwest: Prairie Home Companion hits prime time.

A national pubic radio network began 30-something years ago as a stubbornly out-of-the-mainstream medium. For a long time it was like college radio in corduroy or the alternative press with foundation grants. But over the decades, public radio has passed a series of mile-markers on its path to the middle of the road. Its news correspondents have become mainstream media talking heads. And a no-strings mega-bequest from McDonald's hamburger heir Joan Kroc has helped transform National Public Radio from a network offering maybe 40 hours of programming per week to a full-service network.

Another sign of public radio's ready-for-prime-time status came this summer when Garrison Keillor's A Prairie Home Companion transcended the airwaves entirely and became a movie with actual movie stars and an above-average promotional budget.

For readers who have never heard the show upon which the movie was based (a group comprised mostly of recent immigrants and the very young), look left of the dial at 5 p.m. Central time some Saturday, or go to prairiehome.org any old time. (And, yes, I know that Prairie Home is not an NPR show; it goes up on the parallel "American Public Media" network.)

Keillor's big-city version of small-town culture has been building audience-share and cultural heft for 34 years now. The show was inspired by Keillor's visit to Nashville's Grand Ole Opry, which he was covering for The New Yorker. In its prime, the Opry was a two-hour, three-ring radio circus of homespun humor, commercials for down-home products such as Martha White Self-Rising Flour, and down-home music, which was always in the center ring.

So, for all the critics' references to the influence of Sinclair Lewis, we also have to count among Keillor's true ancestors Cousin Minnie Pearl, who for years regaled Opry audiences with stories of life in her fictional hometown of Grinder's Switch, Tennessee. Pearl ended up as a regular on Hee Haw, a TV-age hybrid born from a forced union of the Opry and The Beverly Hillbillies, but that wasn't her fault.

But the trip from Grinder's Switch to Lake Wobegon was a long and indirect one. Keillor, who is a genuine small-town boy, was also already employed by Minnesota Public Radio and publishing in The New Yorker and The Atlantic. So his version of rural life was bound to have some quotation marks around it. A whiff of irony hung over the show from its very christening. The "prairie home" of the title was taken from the name of a smalltown cemetery. And, this being public radio, the down-home commercials were for fake products.

What Keillor's been doing all these years with his Companion is the same thing that rural American artists have always done: struggle for independence from a culture that also provides their distinctive vision and voice. Think of Mark Twain sitting in his Hartford mansion writing about his Missouri home. Or think of Willa Cather living safely in the East with her female lover while rewriting her family saga of the frontier, or of Faulkner, hiding from his neighbors at the bottom of a bottle while he shipped their darkest secrets off to be published in New York.

Keillor is not quite in the company of those artists, and he knows it. He's not that good, and (maybe the two are related) he's not that alienated. He didn't leave Minneapolis until midlife, and then he only stayed away for about five years. Over the decades of Lake Wobegon tales, his love/hate relationship with his homeplace has veered steadily toward "love."

Part of the difference lies in religion. Keillor was raised in the puritanical rigors of the Plymouth Brethren sect. He left that denomination when he left home. But he never left Christianity. (He's now a communicant of the mainline Evangelical Lutheran Church in America.) If, like me, you've sometimes wondered how much postmodern irony there is in the hymn-singing on A Prairie Home Companion, the answer is not much, at least not for the song leader.

The bonds of faith may take the edge off Keillor's satire. But they also open up a broader field of empathy and compassion for his characters and the tragedy of their lives. And tragedy is what we have left once irony has failed us.

Danny Duncan Collum, a Sojourners contributing editor and author of Black and Catholic in the Jim Crow South, teaches writing at Kentucky State University in Frankfort, Kentucky.