Edison recorded sound onto a tinfoil cylinder, which could be played back on his invention he called the phonograph. As luck would have it, this first public demonstration was obviously not regarded at the time as significant as it turned out to be, since no one saved a copy of the demonstration. An original of the machine was saved for posterity and is now in a museum.

Today, there are collectors of all-things-Edison, including those who specialize in Edison's phonographs, which represent an historic innovation in the history of the recording industry -- to YouTube.

According to the comments on YouTube, this demonstration was made by "master machinist Bill Ptacek in 2001. It's an extremely precise replica of the only surviving original, which is in a museum. Unfortunately Bill was killed in an accident in 2004. He only built 3 of these."

Although the original demonstration of this historic recording by Edison himself was not saved, history did record Thomas Edison performing the demonstration live at the Golden Jubilee of the Phonograph ceremony in 1927. Thomas Edison died on October 18, 1931.

This was not the first-ever sound recording, that being credited to a Frenchman, Édouard-Léon Scott de Martinville, who recorded onto paper a verse of the song "Au Claire de la Lune" in 1860.

Inventing is all about new ways to solve old problems. However, protecting your ideas and leveraging them into patents and products requires good record keeping. When it comes time to patent an idea, build a product, share your ideas or license them for pofit, it's critical that you can prove what you invented and when you invented it.

Scott’s 1860 phonautogram was made 17 years before Edison received a patent for the phonograph and 28 years before an Edison associate captured a snippet of a Handel oratorio on a wax cylinder, a recording that until now was widely regarded by experts as the oldest that could be played back.

Mr. Giovannoni’s presentation on Friday will showcase additional Scott phonautograms discovered in Paris, including recordings made in 1853 and 1854. Those first experiments included attempts to capture the sounds of a human voice and a guitar, but Scott’s machine was at that time imperfectly calibrated.

“We got the early phonautograms to squawk, that’s about it,” Mr. Giovannoni said.

But the April 1860 phonautogram is more than a squawk. On a digital copy of the recording provided to The New York Times, the anonymous vocalist, probably female, can be heard against a hissing, crackling background din. The voice, muffled but audible, sings, “Au clair de la lune, Pierrot répondit” in a lilting 11-note melody — a ghostly tune, drifting out of the sonic murk.