Or rather - the recording of Voices. Thomas Alva Edison is usually regarded as the inventor of this principle, but as a matter of fact several other people had preceded him or were presenting similar devices at approximately the same time.
According to Wikipedia, Edison's Phonograph worked according to the following principle:
Thomas Alva Edison conceived the principle of recording and reproducing sound between May and July 1877 as a byproduct of his efforts to "play back" recorded telegraph messages and to automate speech sounds for transmission by telephone. He announced his invention of the first phonograph, a device for recording and replaying sound, on November 21, 1877, and he demonstrated the device for the first time on November 29 (it was patented on February 19, 1878 as US Patent 200,521). Edison's early phonographs recorded onto a tinfoil sheet phonograph cylinder using an up-down ("hill-and-dale") motion of the stylus. The tinfoil sheet was wrapped around a grooved cylinder, and the sound was recorded as indentations into the foil. Edison's early patents show that he also considered the idea that sound could be recorded as a spiral onto a disc, but Edison concentrated his efforts on cylinders, since the groove on the outside of a rotating cylinder provides a constant velocity to the stylus in the groove, which Edison considered more "scientifically correct"The Phonograph shown here is an original Edison phonograph (slightly restored) belonging to the boy-friend of one of my daughters.
This machine was built in 1904, but the cylinders are not of wax, but made of bakelite. However, I can vouch for the sound - a bit tinny but definitely a song.
PS For more about ABC Wednesday, please visit Mrs. Nesbitt's Place. It is well worth the effort.