Chet Atkins is a little sorry that he changed the face of country music.

"I'm to blame for a lot of that myself," the legendary guitarist sighed as he rode from National Airport to a photo session at the White House yesterday. "Country music moved uptown and it doesn't exist much any more in the old form. I don't know if it ever will."

Atkins, 56, was in town for a ceremony in which one of his custom-built guitars was donated to the Smithsonian. Often referred to as "The Country Gentleman," he's probably been most influential in a 35-year career as the major pioneer of the slick and studied Nashville Sound, and as the producer of country artists as diverse as Jim Reeves, Don Gibson, Charlie Pride and a young rockabilly sensation named Presley. "You couldn't get Elvis off the damn stage with a firehose," Atkins recalled.

"But I want to be remembered as a guitarist," he said yesterday.

No problem there. Few American guitarists have been as influential as Atkins. Millions have heard his unique, classically influenced playing on recordings with Les Paul, Merle Travis, Floyd Cramer and the Boston Pops. For 14 years in a row, he was voted "Best Instrumentalist" in Cashbox magazine. Numerous Grammies and other awards line his Nashville office.

And yet the inevitable artist-producer tensions took their toll. "I made all my albums half-a---d," Atkins confessed. "I'd go home at night, worn out, and sit and fall asleep pickin' the guitar. Then I'd go in the studio and throw 'em down, mostly off the top of my head. I don't ever listen to my records, don't like 'em, can't stand to hear 'em."

At yesterday's ceremony in the Hall of Musical Instruments at the Museum of History and Technology, the soft-spoken Atkins stood awkwardly in front of harpsichords and clavinets while museum director Roger Kennedy sang his praises, summarizing a lifetime in four minutes.

Atkins looked embarrassed at the praise. But he in turn had kind words for 73-year old Hascal "Hack" Haile of Tompkinsville, Ky., who has built him a number of guitars (and who had presented President Carter with a hand-made pocket knife during the White House photo session earlier in the day). Atkins is no stranger to the White House, having first played there in 1961 for President Kennedy. He's no stranger to Carters either: He played with Nashville's Carter Family for several years in the '40s.

Comfort came at last when Atkins stopped talking and started playing. Accenting a sudden rush of patriotic fevor, Atkins developed "America the Beautiful into a swinging lilt before punching out "Stars and Stripes Forever." The playing was straight-ahead, curiously old-fashioned but with a contemporary crispness. It's like some corners of country music today, where folks like Emmylou Harris and John Anderson are reviving older traditions.

"There's still people out there who like the old songs," Atkins admitted. "But Emmylou is a very slick performer with a beautiful voice. She's not a Molly O'Day; it's not country with a rough voice and no beauty."

Nobody could have predicted that the kid from Luttrell, Tenn., who once traded an old pistol for an even older guitar would grow up to be the most influential man in Nashville. It's a power Atkins seems ill at ease with, and a fact he tends to downplay in conversation. "It was an accident," he insisted. "I just happened to be in the right place. I knew a good song, that's all it really takes. And I was kind of square. That helped. Nobody'll remember me 15 years from now. Any good musician would have done the same thing. I was just there."

When he arrived in Nashville in the late '40s, the town hosted radio broadcasts of the Grand Ole Opry and other country music programs, but the music itself was 20 years away from what eventually became the Nashville Sound. There was no studios, no publishing firms, no wealth of pickers and session men. Radio, which gave Atkins his start, "was the greatest thing ever -- people don't realize it because radio's trash now -- great programs where you had to use your imagination to paint a picture. Back when I started, every radio station had local bands, local orchestras . . . it was such good training for musicians and entertainers."

Signed by RCA as a foil to Capitol's success with Merle Travis, Atkins first made records that accented his singing. "They wanted a singer who could sing," he recalled with a wry smile. "I could, of course -- everybody can sing a little. I didn't lie too much." Travis needn't have worried. As for Atkins, he named his daughter Merle. So much for competition.

The early records didn't sell, but Atkins was no stranger to failure -- he'd failed an audition for country legend Roy Acuff's Smoky Mountain Boys and had been dropped as a sideman from more than a few bands. He continued to assimilate the ways of the studio, cultivating friendships with other Nashville musicians, and learning, learning, learning.

The big break came in 1955, when he was asked to co-produce the first RCA single by a new RCA acquisition. "I had my wife come down and look at him. I said, 'You're going to see the greatest thing that has ever hit the music business.' The singer was Elvis Presley. "We had a lot of pressure because everyone said RCA would destroy him, he'd be no good, we couldn't get that Sun sound. We got it, but Ithink we overdid it a bit."

Their success with Elvis convinced RCA to build a studio in Nashville in 1957 and to put Atkins in charge of it. He has been vice president of the label's country-music division since 1968. Atkins' work at the helm of the studio in those intervening years forever changed the face of country music. Atkins weaned the genre away from its traditional regional audiences and developed its national appeal by making it more palatable: fuller, lusher arrangements, elimination of the fiddle and banjo, which were replaced by the piano and strings; a more relaxed, tensionless sound.

Along the way, Atkins produced a host of artists, many of them outside the country field: Hank Snow, Don Gibson (his first effort here yielded a single with two classic hits, "Oh Lonesome Me" and "I Can't Stop Loving You"), Perry Como, Trini Lopez, Waylon Jennings, Dottie West, Roger Miller, Roy Orbison, Al Hirt. The list goes on and on, and the effect was incredible.

But for all the changes he's wrought in the industry, Atkins still leans toward the older, more traditional values and styles in country music. "I would hate to see it die completely," he said. "Pop music and country music are the same now. The only difference is an accent here or there." One almost hears an apology in Atkins' voice. He's self-effacing to the end: "In Nashville, I just have an office. I tell 'em they've gotta see somebody else. I'm playing guitar now, and that's what I always wanted to do anyway."