Software programmers speak in code, accountants in numbers. But at Fur Peace Ranch's guitar camp in the Appalachian hills of southeastern Ohio, they speak 12-bar blues in the key of E.

The conversation goes on well past midnight — hours after the workshops end. Micky Rigby, 57, a banker from Little Rock, Ark., starts with a riff on his Taylor acoustic guitar, and soon the rhythm swells like a warm Delta breeze. A thump, a slap, a twang and a new verse begins. Others answer in kind.

At Fur Peace, a music school dedicated to studying guitar and roots music, classes fill up early. The popularity of this camp and others like it is mirrored by the explosive popularity of the instrument itself. The guitar is the top-selling musical instrument in the United States, with more than 3.3 million acoustic and electric models sold in 2004, up 40 percent from the year before.

Even in 1998, the first campers were forty- and fiftysomething professionals, says owner and president Vanessa Lillian Kaukonen. Initially, they were attracted by the camp's marquee instructor, Vanessa's husband, Jorma Kaukonen, guitarist for Hot Tuna and a founding member of Jefferson Airplane.

The fingerstyle-blues workshop is the most popular (there are also workshops on jazz, funk and classical styles), but I attend JamStock: an electric guitar jamathon that teaches how to interact onstage — think volume, soloing and jam etiquette. It is taught by Michael Falzarano, who has performed and recorded with Hot Tuna, John Lee Hooker, Dr. John, Greg Allman and David Crosby, among others.

At first the class is raucous. Some players are overamped, and others are overexcited. But by the second afternoon, the students find their groove.

Rigby, a four-workshop veteran, explains what draws him and others to places like Fur Peace. "We're here for a total release and to do something we love to do. We all have day jobs, and most of them aren't very exciting. I'm a banker. And if you don't have a creative outlet, you wake up one day and you're 65 years old with nothing better to do than walk the mall in shoes with Velcro closures. That's not a pretty picture."

Fur Peace Ranch's 2006 schedule includes 63 workshops over 16 long weekends (Friday to Monday) from March through November. A typical workshop runs four days and costs $950. For more information, visit www.furpeaceranch.com or call 740-992-2575. For other music camps, go to kiplinger.com/magazine/links.