Tom Paxton went off to the University of Oklahoma in the mid-'50s to study drama with the intention of becoming an actor. But by the time graduation rolled around, he was already a folk singer and a budding songwriter to boot. "Believe me," he confesses, "the theater didn't lose anything when I changed my major, so to speak."

Maybe not. But folk music was certainly the richer. By his own count, Paxton -- who appears tonight with Bob Gibson at Baird Auditorium -- has written in the neighborhood of 1,500 songs, though he'd be the last to call that figure significant.

"All that counts," he explains, "are the songs that anyone would want to sing. I would say of that number there are maybe three or four hundred songs that I take a certain measure of satisfaction in having written."

Paxton began writing songs almost from the time he picked up a guitar when he was 16, inspired by fellow Okie Woody Guthrie, Pete Seeger, the Weavers and Burl Ives, among others.

"My interest in folk music was really lifelong," Paxton says, "though I didn't know you called them folk songs at the time. I'd hear these songs that I just happened to like a lot and I gradually came to understand there were a lot of them and they were called folk songs. When I got to college I began meeting up with friends who liked the same kind of songs, and my interest got deeper and deeper until folk music was much more important to me than trying to become an actor."

After college the Army beckoned, and for a time Paxton was stationed outside New York City. Drawn to Greenwich Village on weekends, he began haunting the clubs where the '60s folk boom was just beginning to take shape. Soon he was playing alongside Phil Ochs, Dave Van Ronk, Ramblin' Jack Elliott and Mississippi John Hurt at the Gaslight.

"It was marvelous," Paxton recalls. "My first job at the Gaslight involved my coming to work at midnight and staying until 6 in the morning. They used to stay open all night. Typically, there would be five or six of us on the bill and you'd do six or seven short sets a night." Paxton was performing "in and out" of the Gaslight for the first couple of years, but following his stint in the Army he worked there for nine months straight in 1962. He wrote "Ramblin' Boy" between sets there one night, and performed his classic "The Last Thing on My Mind" for the first time at the club.

Though he was surrounded by talented songwriters and musicians his own age, and remembers sitting with Van Ronk at a Folk City hootenanny the first time he saw Bob Dylan perform, it was the older generation of musicians that really impressed Paxton. "When I heard people like Doc Watson or John Hurt, I knew I was hearing the best," he says emphatically.

Looking back on how long it took him to land a recording deal -- at a time when virtually anyone toting a guitar through the Village was likely to be signed up by a label -- amuses Paxton. "It took four years -- four years when everyone had a contract but me," he says, feigning outrage.

Paxton has since made up for those years, however. Beginning with seven albums for Elektra, he's recorded consistently over the past two decades. His more recent work can be found on the Flying Fish label (or its associated labels), and his tunes remain richly varied, ranging from children's songs to love ballads to broadsides. His satire is as sharp as ever (he credits Tom Lehrer as a big influence in that department), and the years he spent living in England in the '70s heightened his appreciation for political and social commentary.

Writing requires a special kind of listening, Paxton says. "You listen for words, for a tune, for an idea. I don't want to sound artsy, but it's a kind of inward journey. I think the computer analogy holds up well. It's a matter of giving a problem to your subconscious mind to work on. Songwriters are programmed to think in terms of songs, so it's really just a matter of problem-solving."

Not surprisingly, his favorite song is "everyone's favorite -- 'The Last Thing on My Mind.' I'll never write another song that will have the universal appeal that song has had," he says flatly. "It's a miracle to write a song with that much appeal in a lifetime, so you might as well forget about doing it again."

With one daughter at Yale and another college-bound, Paxton jokes that he has to keep touring these days. Happily, he finds that the climate for folk music has seldom looked brighter. The rising number of folk music societies active around the country and "a fine crop of new talent," which includes Christine Lavin, Suzanne Vega, John Gorka and Charlie King, are two good reasons to be optimistic, he says.

"There is one thing I would like to see more of, though," he adds. "There seems to be a real dearth of young interpreters of traditional songs. It's important to put the music in perspective. But I guess the music moves in cycles. Sooner or later some bright young person is going to stumble on all those old 1960s English revival records and start another whole new thing going."