An undisputed icon in country music history -- a Gibson L-5 acoustic guitar previously owned by Country Music Hall of Fame member Maybelle Carter -- is up for sale with a $575,000 price tag. Constructed in 1928, the archtop guitar is being offered by Gruhn Guitars, a Nashville shop specializing in the sale of vintage stringed instruments.

George Gruhn, an internationally recognized authority on appraising instruments, describes it as "the most important single guitar in the entire history of country music."

Carter, who died in 1978, is the mother of the late June Carter Cash. Maybelle Carter first recorded in 1927 with her brother-in-law and sister-in-law, A.P. and Sara Carter, in Bristol, Tenn. Produced by talent scout Ralph Peer, those recordings of the Carters and Jimmie Rodgers became known as the Bristol Sessions and are widely acknowledged as the single event that sparked the development and popularity of country music.

In 1928 alone, the Carter Family released two of its most famous songs: "Wildwood Flower" and "Keep on the Sunny Side." In The Encyclopedia of Country Music, compiled by the Country Music Hall of Fame and Museum, historian Charles Wolfe writes, "Maybelle Carter crafted the 'Carter lick' on the guitar and watched it become the best-known picking style in the genre."

In explaining the historic significance of Carter's L-5 guitar, Gruhn tells CMT.com, "It was the guitar she used for virtually all of her recordings from 1928 until she died. Virtually every classic Carter Family tune ever recorded, with the exception of the Bristol Sessions, was all done on this guitar."

Gruhn declined to discuss how the guitar came to be for sale although he did confirm that he is brokering it on behalf of a Carter heir. While many people have assumed that family members donated the guitar to the Country Music Hall of Fame, Gruhn says, "They never did. It was loaned."

In setting the asking price, Gruhn admits, "It is extremely difficult to come up with anything in the way of a true ironclad rule for pricing memorabilia. I can at least say that Bill Monroe's mandolin had a deal going at $1 million. That [deal] has kind of fallen through, but it's still the asking price for the mandolin."

All things considered, $575,000 doesn't sound like an unreasonable price. Gruhn explains, "By comparison to George Harrison's rosewood Telecaster [a Fender electric guitar] -- which went for over $900,000 at auction and was certainly not even his primary guitar -- it's a bargain. Or compared to Jerry Garcia's [Doug] Irwin guitar -- which was one of his primary guitars but certainly not his only one by any means -- that one went for $950,000 at auction. ... And while it's hard to compare Maybelle Carter with Jerry Garcia, the point is that Jerry had dozens of guitars and, frankly, Jerry didn't have such a unique style that everybody's copying the 'Garcia style.'"

The Carter guitar style continues to influence musicians, including non-country players. "You have to figure that Woody Guthrie basically took Carter tunes and wrote his own lyrics," Gruhn says. "And Bob Dylan went after that. Maybelle went on to influence the whole folk music boom and right on through Dylan and everything else. Maybelle is far more influential than a lot of people realize because a lot of people who never heard a Carter Family record are still influenced by her today. She may well be the single most important influence on American folk guitar that ever was."

As for a potential buyer for the Carter guitar, Gruhn says, "It's certainly entirely possible that a group of donors might pool their resources and donate it the Hall of Fame or another museum -- which I think would be a wonderful thing to happen."

In a recent interview with CMT.com, acoustic guitar master Norman Blake talked about his work with the Carter Family -- and about Maybelle's guitar.

"That's a talisman," he said. "All guitars are that way. I've seen it written in some guitar books that even if you don't know the celebrity connections to ... old stringed instruments like that, everybody that's ever had contact with it kind of put something in it and on it."

Gruhn probably wouldn't disagree.

"It is a wonderful guitar," he says. "I can tell you: You pick it up, and it automatically seems to want to play Carter tunes."