WASHINGTON (Reuters) - U.S. audio historians have discovered and played back a French inventor’s historic 1860 recording of a folk song -- the oldest-known audio recording -- made 17 years before Thomas Edison invented the phonograph.

“It’s magic,” audio historian David Giovannoni said on Thursday. “It’s like a ghost singing to you.”

Lasting 10 seconds, the recording is of a person singing “Au clair de la lune, Pierrot repondit” (“By the light of the moon, Pierrot replied”) -- part of a French song, according to First Sounds, a group of audio historians, recording engineers, sound archivists and others dedicated to preserving humankind’s earliest sound recordings.

It was made on April 9, 1860, by Parisian inventor Edouard-Leon Scott de Martinville on a device called the phonautograph that scratched sound waves onto a sheet of paper blackened by the smoke of an oil lamp, Giovannoni said.

Giovannoni said he learned on March 1 of its existence in an archive in Paris and traveled to the French capital a week later. Experts working with the First Sounds group then transformed the paper tracings into sound.

“It’s important on so many levels,” Giovannoni said in a telephone interview. “It doesn’t take anything away from Thomas Edison, in my opinion. Thomas Edison is generally credited as the first person to have recorded sound.”

“But actually the truth is he was the first person to have recorded (sound) and played it back. There were several people working along the lines of Scott, including Alexander Graham Bell, in experimenting -- trying to write the visual representation of sound before Edison invented the idea of playing it back,” Giovannoni said.

The recording will be presented on Friday at a conference of the Association for Recorded Sound Collections at Stanford University in California, Giovannoni said. It is also posted on the Webhere.

The U.S. experts made very high-resolution digital scans of the paper. First Sounds said that scientists at the Lawrence Berkeley National Laboratory in California converted these scans into sound using technology developed to preserve and create access to a wide variety of early recordings.

“It’s like discovering the world’s oldest photograph and learning that the photograph was taken 17 years before the invention of the camera,” Giovannoni said. “In this case, the oldest sound that we can generally hear, up until today, has been from 1888. This predates it by 28 years.”

Giovannoni said that phonautograph recordings were never intended to be played.

“What Scott was trying to do was to write down some sort of image of the sound so that he could study it visually. That was his only intent,” Giovannoni said.