CURRENTLY THE HOTTEST GROUP IN THE U.S. popular music is the Kingston Trio, three college grads in their mid 20s who sing and strum such native tunes as "Tom Dooley" (3 million copies), Ban Man Blunder (5000,000 copies) and other semi-folk songs of that ilk.

Their long-playing albums, which supply Capitol Records with 15 percent of its annual sales, have ranked No. 1 or No. 2 on the bestseller lists week after week. Their one-night stands (approximately 300 a year) are good for $5,000 to $7,000 a night. Their contract fir TV and radio commercials nets them $250,000 a year.

Any time they can overcome their moral aversion to Las Vegas -- "We prefer just a little more wholesome environment" -- the Trio can pick up another $25,000 a week. The boys are also in demand by every film studio in Hollywood and every TV variety program in the country.

For pop singers such a success story is nothing new or startling. Bing Crosby, Frank Sinatra, the Andrews Sisters, Elvis Presley, Bobby Darin and others have made the jet blast from anonymity to sudden fame.

What makes the Kingston Trio so refreshingly welcome to the show business scene is that they are normal, decent, intelligent, educated, clean-cut, wholesome, happily-married Americans.

Unlike some singers who are frustrated "hoods" or members of a "clan," they do not surround themselves with sycophants or stooges. They refuse to traffic with the underworld, while controls many U.S. night clubs. All three families are regarded by the northern California communities in which they live as honorable civic minded citizens.

The Kingston Trio consists of Dave Guard, 26 ("the tall one and our acknowledged leader,") Nick Reynolds, 27 ("the runt of the litter,") and Bob Shane, 26 ("our sex symbol.")

Guard and Shane both come from Honolulu, where they attend Punabon School together, clowned around on the beach at Waikiki, learned how to play ukuleles and sing native songs. In 1952 Guard went to Stanford University, majored in economics, supported himself by washing dishes, waiting on table, singing in a near-by Bavarian-type restaurant. Shane enrolled in Menlo Park College, a stone's throw from the Stanford campus, majored in business administration, was graduated in 1956.

Nick Reynolds hails from San Diego, son of a U.S. Navy Captain. A graduate of Coronado High School, where he played tennis and basketball, Nick matriculated at the University of Arizona, transferred to Menlo where he met Guard and Shane.

Music Before Money

How come three such well-educated young men decided to enter show business rather than seek careers as bank executives, stock brokers or business tycoons?

Dave Guard, spokesman and music selector for the trio, says: "The three of us decided that the nine-to-five world was simply not for us. Bob and I were raised in Hawaii where early in life we learned that happiness and music came before money. Nick Reynolds is a Navy brat, and in the Navy they measured success by rank, not money. In addition, Nick's old man plays a very swinging guitar, which shows that Navy captains are human too. We happen to be three guys who love music more than we love business administration. And fortunately we can make a good living doing what we love."

The Kingston Trio got it's start one spring evening in 1957. The boys ambled into the Cracked Pot, a nightspot near the Stanford campus, offered to entertain for free beer and pretzels. As they took guitars and banjo in hand, Frank Werber, press agent for a small night club called the "Hungry i," listened attentively. When the Trio finished, Werber introduced himself, subsequently signed them to a personal management contract written on a paper napkin. The deal: 25 percent for each member of the Trio, 25 percent for Werber.

Werber took his young charges to Judy Davis, well known San Francisco vocal coach, rehearsed the boys until their harmony was near perfect and their repertoire consisted of three hours of songs. Then he booked them into San Francisco's "discovery nightclub" a showcase for new talent (Mort Sahl, Shelley Berman, Ronnie Schell,) called The Purple Onion.

The boys tried out for a week, and stayed for seven months. Word-of-mouth had them tabbed as "the hottest singing trio in the business." Offers came from such clubs as Mr. Kelley's in Chicago, The blue angel in New York. The Kingston Trio was on its way.

In January 1958, Capitol Records signed them to a long-term contract, but their first album, entitled "The Kingston Trio," was no smash hit. In the album, however, was a century-old folk song based on a Confederate two-timer named Thomas Dula, who murdered his old sweetheart when he found a new one. Called "Tom Dooley," the song aroused so much interest that the record company released it as a single. "Tom Dooley" zoomed to the top of the best-seller lists. In three months, more than 1 million copies were sold.

The Kingston Trio became even hotter. Dinah Shore, Perry Como, Gary Moore, Patti Page -- all of them signed the boys for their shows.

The College Trade

Because the songs they sing and play are intelligent songs with a message -- "We won't sing a song that is not founded on intelligent motivation and good taste," says Dave Guard -- the boys suggested to manager Frank Werber that he book them into universities for college concerts.

"We felt," explains Nick Reynolds, "that we had some rapport with the college crowd, that they would go for us and we for them.: They couldn't have been more right. For the next six months the trio averaged one college concert every two days.

"What the Kingston Trio has done," explains a Capitol Records executive, "is this: They've succeeded in tapping the most untapped music market in the country -- the college trade. Today there's hardly a fraternity house in the nation that doesn't boast at least one Kingston Trio album. College boys and co-eds identify with Dave, Nick and Bob, because they're clean-cut, intelligent, well-behaved."

When I asked the Trio how they analyze their success with the college trade. Bob Shane told me: "Twenty or 30 years ago, the big-bangs like Artie Shaw and Glenn Miller were in their heyday. They went from campus to campus for the big dances. But over the past decade of so the big name bands have faltered, and entertainment of the college crowd has lost stature. That's why we cater primarily to that crowd, and they welcome us. We also have a following among teenagers and middle-aged people, but the teenagers comprise a pretty fanatic audience. They're not nearly as well mannered or attentive as the college kids."

To date the Kingston Trio has made seven albums, each selling nearly half a million copies. The boys work in a 5 percent royalty, earned a million dollars last year from all sources. In addition they own their own music publishing company and recently plunged into real estate, buying the Columbia Tower building in San Francisco for $350,000.

Having majored in business administration they know about taxes, depreciation, capitol gains and mortgages. They have a weather-eye cocked for other favorable real estate deals and talk longingly of their "cut-off date." This is the date they plan to leave show business and settle down with their wives and children. The three singers have fathered among them three-and-a-half children, and are interested in a variety of activities ranging from the collecting of historic guns to modern painting.

The "cut-off date," they say will come when each member of the Trio has amassed at least $500,000.

"If you've got half a million bucks invested in tax-exempt municipal bonds at 4 percent," suggests Dave Guard, "that means you've got a tax-free annual income of $20,000. For guys like me and Nick and Bob who used to sing for beer and pretzels three years ago -- well, that should be enough."