The guitar is not a Celtic instrument, but in the hands of guitarists Steve Baughman and Robin Bullock, it becomes one.

"That's one of the things that makes it so fascinating," Bullock says. "Steve and I both have been focused on Celtic music and guitar at the same time."

The two will present the "Celtic Guitar Christmas Show" on Dec. 13 at Randy's Pickin' Parlor in Bloomingdale.

"The guitar is not part of Irish or Scottish tradition," Bullock says. "It sort of entered the picture during the 1960s during the folk boom.

"The typical instruments of Irish tradition are the fiddle, flute, pipes and accordion. The guitar was an outsider and part of the challenge Steve and I have both been exploring and having fun with.

"We're making the instrument sound like it belongs to that tradition," Bullock says. "We borrow techniques from fiddlers and pipers and use them on the guitar."

Adding to the challenge is that while Bullock is based in Asheville, N.C., Baughman is based in California. The two met as instructors at the 2000 Swannanoa Gathering's Guitar Week, a music camp in Asheville.

"When we first played together, it was astounding," Bullock says. "We sat and played few tunes and there was an immediate instrument and personal chemistry.

"It felt like we'd played together all our lives. It was almost like we had to play together.

"The guitar in and of itself is not a typical Celtic instrument," he says. "It might be we're the only ones doing it. Certainly, there aren't many."

What Baughman and Bullock have found is that two guitars can create an otherworldly Celtic sound. Each has the perfect background to create such music.

Baughman is the author of the Mel Bay books "Celtic Guitar Method," "Celtic Fingerstyle Guitar Solos," "An Open Tunings Christmas" and "Frailing the Guitar." He has recorded three solo CDs, "A Drop of the Pure," "The Angels' Portion" and "Old World Christmas," and appears with guitarists Pierre Bensusan, Martin Simpson and El McMeen on the Rounder Records Celtic Fingerstyle Guitar CD/video series "The Blarney Pilgrim" and "Ramble to Cashel."

Bullock is a composer and multi-instrumentalist who plays 6- and 12-string guitars, cittern, mandolin, piano and bass guitar. He is a founding member of the world-music trio Helicon and has toured extensively throughout the United States, Canada and Europe.

Bullock has appeared on more than 50 CDs, including four solo CDs, "Green Fields," "Midnight Howl," "Between Earth and Sky" and "The Lightning Field."

"I grew up in a musical family," Bullock says. "I'm the only one who took it to the point of playing professionally.

"We grew up singing in the choir," he says. "There was always a piano and guitar and violins laying around."

Bullock says he knew "right away" that he wanted to be a professional musician.

"I think it was seeing Glen Campbell on TV when I was 6 or 7 years old," he says. "That looked like the coolest thing I could ever imagine. My parents, God bless them, bought me a cheap guitar."

After starting to play, Bullock didn't have much direction until he was 12 and heard Doc and Merle Watson perform.

"Immediately, it blew the doors open," Bullock says. "This was so much deeper and more powerful than anything I'd heard before.

"That's how I got into traditional music," he says. "Doc was the one who gave me the initial inspiration, and then Norman Blake, John Fahey and every Scottish or Irish musician I ever heard kept me going."

Baughman and Bullock knew each other by reputation, but had never met.

"We played the same kind of music," Bullock says. "There was this spark that was amazing to both of us. We weren't trying that hard, but it was like long-lost twin brothers."

The sound created by the two is unique, Bullock says.

"It's not just the sound of two guitars," he says. "Both of us use ultra tunings in an ongoing attempt to get closer to the Celtic harp or pipes or fiddle.

"When you have two guitars in altered tunings, you get an amazing resonance with this huge, big sound," Bullock says. "There may be other duos out there doing this, but we may be the only one."

The two did their first album 12 years ago.

"The recording company insisted on calling it 'Celtic Guitar Summit,'" Bullock says. "We jokingly referred to it as 'Celtic Guitar Somewhat.'

"It came together very easily. Three editorial writers at Acoustic Guitar magazine picked it as one of the Top 12 of the year."

The distance between the two has meant they haven't been able to record again until this year.

"We have a brand-new CD coming up, 'Alone and Together,'" Bullock says. "Each of us recorded three solo tracks and did the rest together."

Because of the coast-to-coast distance between the two, the upcoming concert is a rare opportunity to see them perform together.

"We'll be playing a fair amount of music for the season," Bullock says. "We'll do familiar Christmas carols and we'll be playing a lot of music from the Celtic tradition.

"It will be mostly on two guitars, but I also play cittern and mandolin and Steve plays banjo," he says. "We will be switching back and forth."

The two are really excited about the concert, Bullock says.

"What a kick it's going to be coming to Savannah for the first time," he says. "And it's a thrill to be playing at Randy Woods' Pickin' Parlor.

"I've never met him, but I've known about him for years," Bullock says. "He's a legend as a repairman and instrument builder and I'm looking forward to meeting him."