"I always figured I would die a tragic death at an early age," sighs singer-songwriter Tom Rush. "I guess I've blown it."

Rush, at 40, still looks like the Harvard undergraduate he was 20 years ago; somewhere in his re'sume' there must be an aging publicity photo, yellowing and curling up as it records miles traveled, records made, songs written and songwriters discovered. The Tom Rush sitting in the office at The Door in Georgetown is fit as a Martin D-28, jeaned and comfortably jacketed, the Hillsboro, N.H., gentleman farmer in the city for a little business.

"It's been clean living," he grins. "That's the secret." The Door holds a special spot in his heart; it's where he met his wife, Beverly, 10 years ago. Rush was a hotter commodity then, still building on a career that had started in the early '60s Cambridge folk scene. He was neither traditionalist nor revivalist, but the "folkie" label is one that's been tied to Rush since Day One.

"I only mind it depending on the climate of the year, whether folk music may or may not be easy to sell," he shrugs. "There are times when it's good to be a folk singer and times when it's not. Even in my 'folkie' days, I did a variety of music. When most of the guys were concentrating on blues or ballads or Woody Guthrie songs, I picked one of each and put together a patchwork of songs that I liked."

When he expanded his eclectic repertoire with new material, Rush managed to discover some outstanding young writers -- he was the first to record songs by Joni Mitchell, Jackson Browne and James Taylor. "I never did seek out new songwriters," he insists, "I was looking for songs. Of course, some of those people did go on to make a lot of noise."

Rush met Mitchell in a Detroit coffeehouse. "The owner said this girl wanted to do a guest set, that she played there regularly. I was just knocked out, even tried to convince Jac Holzman president of Elektra, Rush's label then to sign her. He said she sounded too much like Judy Collins also on Elektra . I tried to persuade Judy to do some of her songs . . . and failed. Of course, later, Judy had her biggest hit with Joni's 'Both Sides Now.' "

Elektra had Browne's publishing rights and "for quite a while he wasn't even interested in a recording career; when he finally did come around, he came around big." Taylor finally arrived after Rush had been rooming for several years with a member of the Flying Machine, Taylor's first band. "He kept telling me about this great new songwriter but I never made the connection."

"In a way, I regret the reputation for discovering songwriters because I get tons of tapes in the mail. I don't have time to listen, so they accumulate in barrels. They send me 40 of their best songs and want a detailed critique."

For the last 18 months, Rush has been doing some critiquing and analysis of his own, trying to understand why he hasn't had an album since "Ladies Love Outlaws" on Columbia five years ago. "The big problem with the record industry is that they can't sell records to people between 25 and 45 years old. They just write them off . . . and I think that's stupid. That's half the people in the country, the same individuals who built the industry by buying the Beatles and Presley. Everybody in business sells to people over 30 -- except the record industry."

For the first 17 years of his career, Rush was not interested in the business side: "As long as the money came in as fast as it went out, I was happy." When that started dwindling, he took business courses, started market surveys at his concerns. A recent sold-out Symphony Hall concert in Boston was "a proof of concept venture. It doesn't mean Tom Rush is in an upswing. It means there's a very frustrated audience out there that would really like to go to shows if somebody would only give them shows they want to go to."

The singer also recalls a $90,000-a-year Columbia Records executive standing up at a meeting, talking demographics and saying, "Maybe the reason they're not buying records is we're not making records they want to buy." He shakes his head.

Rush performs eight to 10 days a month (a vivid contrast to five straight years on the road in the late '60s), recording new material in the 16-track studio he built on his 600-acre New Hampshire farm. The urge for going seems less insistent than during his undergraduate days, when he set out three times for California. "Made it to New York the first time, Philadelphia the second and Florida the third," Rush laughs. "Geography was never my best subject." (He graduated from Harvard in 1964 with a degree in English literature.)

He seems at peace, unworried by the success that enveloped those he discovered ("proves I had good taste and still leaves me something to look forward to") or the "folkie" label that may have limited his career. "It's always been difficult to say what kind of music Tom Rush does," says Rush. "But it's been a blessing because it keeps me interested and it keeps my audience interested. It gives me license to experiment."

The lanky singer remembers his junior year at Harvard, when he dropped out and "spent some time trying to figure out if I could make a living singing -- or if I wanted to. The answer was a marginal yes." And evidently correct.