IN THEIR brief reign as the world's first prefab pop group, The Monkees--Mickey Dolenz, Peter Tork, Mike Nesmith and Davy Jones--had a three-year run with their NBC television series, cut 10 gold records, including "Last Train to Clarksville" and "Daydream Believer," and made a flop movie with Bob Rafelson called "Head" that still enjoys cult film status. The group dissolved in 1969, and although none of the four have maintained their previous high profiles, each has kept some contact with the music world.

Peter Tork, the "third most popular Monkee" (as measured by NBC fan mail), is now fronting a 3-month-old quartet called the Peter Tork Project, his 12th band since the Monkees broke up. Tork will play two shows at the 9:30 club Saturday. At 37, he retains traces of his goofy persona and the hippie-dippy humor seen on the TV show.

"Before the whole Monkees thing happened I was living in California, playing banjo and guitar with a folk trio called the Phoenix Trio, and sometimes playing in Greenwich Village cafes," says Tork, who was born Peter Thorkelson here in Washington. It was during his Village days that Tork befriended Steven Stills (later of Buffalo Springfield and Crosby, Stills and Nash), who indirectly landed Tork the Monkees spot.

In 1966, Columbia Pictures and NBC decided to create a television series, blatantly imitating the Beatles' highly successful movie debut, "A Hard Day's Night."

"The story about the ad placed in the newspaper is true enough," Tork says, "but of the four of us, Mike Nesmith is the only one who saw it." About 430 hopefuls responded to a newspaper advertisement announcing auditions for the new series, including Stills, Danny Hutton (later of Three Dog Night) and John Sebastian (of the Lovin' Spoonful). "They told Steve, 'Your hair and teeth aren't photogenic, but do you know anyone who looks like you that can sing?' And Steve told them about me." Tork was the last to be hired.

Immediately after hitting the air in September 1966, "The Monkees," under the direction of Don Kirshner, became a success both on television and radio, and the group made hits out of songs by some of pop's top songwriters, including Carole King and Gerry Goffin, Tommy Boyce and Bobby Hart, Neil Diamond, Jerry Leiber and Mike Stoller, and Neil Sedaka.

At first the musical tracks were recorded by studio musicians, and the Monkees provided only the vocals, but after the group "threw a fit farther than you could throw a fit," Kirshner gave in and let them play their own instruments, despite the fact that only Nesmith and Tork had any kind of musical background. "We were stinging from the cries of 'phony pop phenomenon,' " Tork says. "Actually, Mickey and Davy didn't notice a thing. They were actors. But Mike and I were raised with a certain tradition of idealism and it bothered us then."

By his own estimation, Tork says he rapidly grossed, and just as quickly spent, more than $1 million, including merchandising and record royalties. "I was a very young man, and I lived through all that hoopla without a core. I thought it would last," Tork says. "So I spent my money grandiosely, and other times I gave it away in abject humility. And what taxes didn't take went to unscrupulous persons of one stripe or another."

In the 15 years since the Monkees broke up, Tork estimates he has worked in a dozen rock bands, including a 35-voice "Aquarian age gospel music" choir. Tork also worked as a teacher for three years in southern California, teaching English, math, drama, "even typing--I do a mean 50 words per minute," he laughs. Tork now lives in Venice, Calif., with his wife and children, but says he must spend most of his time in New York to keep his career going.

Tork is now realistic about using his connection with the Monkees. "For a long time I refused to touch that material. I had this ridiculous pride thing," Tork says. "But I've gotten over that. Who was I kidding? If I went to a show by any former Monkee, I would want to hear Monkees' hits. We the Tork Project play a hefty portion of Monkees tunes, and the arrangements are essentially the same, maybe a bit bigger and tougher instrumentally."

Tork says he never kept Monkees mementos--all he has are a few old Monkees records, including a few in Japanese. Although none of the quartet have remained in touch, Tork says Mickey Dolenz is directing video and small-theater productions in London; David Jones is breeding horses and doing music hall revues featuring old Monkees tunes, also in England; and Mike Nesmith, the only ex-Monkee to make a name for himself musically, is still making country-tinged music and producing videos in Los Angeles.