IT WAS JUST a collector's notion at first, and a rather peculiar one at that. Imagine commissioning the world's greatest luthiers to create a series of archtop guitars, each uniquely designed but all cast in the same shade of lightning blue.

Yet it wasn't long before the notion became a reality -- a 22-piece collection called "Blue Guitar," thanks to collector Scott Chinery's patronage and the participation of nearly two dozen renowned instrument makers from around the world. Then, last fall, "Blue Guitar" became a Smithsonian exhibition and the inspiration for an ongoing series of virtuoso jazz guitar concerts at the Institution. A book, also titled "Blue Guitar," quickly followed, profusely illustrated with images of each luthier's intricate and inspired handiwork.

And now, to commemorate the 100th anniversary of the archtop guitar, the Smithsonian is celebrating the "Blue Guitar" exhibition with a two-day event this weekend. On Saturday, several luthiers will discuss their work and conduct master classes at the Smithsonian. On Sunday, an extraordinary array of jazz guitarists will gather at Wolf Trap to play the Blue Guitars as well as their own instruments. Hosted by John Pizzarelli, the concert will feature performances by George Benson, Martin Taylor, Kenny Burrell, Larry Coryell and Andy Summers, among others. Also present will be jazz guitar great Johnny Smith, who will receive a lifetime achievement award from the Smithsonian.

All agree that the archtop guitar, an acoustic instrument modeled after the violin and cello -- hence the carved arched top and f holes -- and favored by jazz guitarists since the advent of the swing era, is enjoying a long overdue renaissance.

"I think it's marvelous that Scott would do something like this because we're faced with such a hideous dumbing-down of everything," says Summers, the former guitarist for the Police and now the leader of his own venturesome jazz-rock ensemble. "For someone to act as a patron to all these great luthiers in today's world and give them this kind of exposure, I think we really need that sort of thing."

As a teenager in England, Summers pursued his passion for jazz by learning to pick out the solos on recordings by Jim Hall, Wes Montgomery and Barney Kessel on a cheap archtop guitar. "I have a lot of guitars," he adds speaking from his home in Los Angeles, "but the ones I've spent the most money on -- sort of collecting -- are old archtops. . . . It's a classic sound, no effects, just bass, treble, mid-range, a small amp, and that's just what it is."

With its woody and mellow tone, Summers found that the archtop was ideal for quietly studying the intricacies of jazz harmony, lessons that would later influence his work with the Police. "The genesis of the band was during the punk movement -- '76 and '77 -- when corporate rock bands disappeared overnight. So for a few months -- the cycles were fast back then -- we played punk to pay the rent."

Soon enough, though, Summers discovered that he could incorporate jazz harmonies into the band's swiftly evolving sound. "I started to realize that Sting had incredible ears. He could hear all of these outside harmonies and it wouldn't throw him off. I could play more fragmented, more unconventional harmonies over the framework of a pop song."

In concert these days, Summers plays a thinner, hollow-body Gibson, mainly because archtops create feedback in settings that require a lot of amplification, but after recently playing one of luthier Robert Benedetto's archtops, Summers commissioned a Benedetto on the spot.

Of course, he may have to wait a while for its arrival. Despite the cost of his instruments -- they range in price from $20,000 to $50,000 -- Benedetto keeps 70 to 80 orders on his books at all times. Typically, the wait for an instrument is three years, but since he's considered by many players and collectors as a modern day Stradivarius, no one's complaining.

Contemporary luthiers and old world violin makers do have strong ties, says Benedetto, who has been practicing his trade for 30 years. "I don't think there is an archtop guitar maker who isn't thinking violin," he says from his home in East Stroudsburg, Pa. "From the very beginning the wood selection is identical -- a spruce top and a curly maple or flamed maple back, preferably the European varieties. The carved top and back and front starts out as one-inch wood and may end up as little as four millimeters thick throughout, with very subtle gradations."

As a child, Benedetto found the shape of an archtop guitar so appealing that he began carving miniature instruments out of the pieces of scrap wood he found in his father's furniture shop. "It's all I ever really wanted to do," he says. "It just has a magical quality for me."

Not surprisingly, when Chinery, whose collection includes more than a thousand instruments, asked for a "Blue Guitar," Benedetto regarded the commission as a dream assignment -- a chance to create "the most pure acoustic archtop" he could make. "That was the challenge," he says. "Now I had the freedom to do things I could only think about doing before." BLUE GUITARS -- "Blue Guitars Makers' Display," Saturday from 11 to 4 in the Hall of Musical Instruments at the National Museum of American History, 14th Street and Constitution Avenue NW. Admission is free; call 202/357-2700 (TDD: 202/357-1729). On Sunday, a concert featuring George Benson, Andy Summers, Kenny Burrell, Martin Taylor, Ron Affif, Mark Whitfield and Larry Coryell, with emcee John Pizzarelli is held at Wolf Trap. * To hear a free Sound Bite from Andy Summers's "The Last Dance of Mr. X," call Post-Haste at 202/334-9000 and press 8101. (Prince William residents, call 690-4110.) CAPTION: Andy Summers finds the archtop ideal for intricate jazz harmonies. CAPTION: Luthier Robert Benedetto shapes the neck of one of his creations.