Edison Announces Phonograph: Sound Can Be Recorded

Thomas Edison shouted "Mary had a little lamb" into a metal cylinder wrapped in tinfoil, turned a crank, and heard his own voice played back to him. The phonograph, announced on November 21, 1877, stunned even its inventor. Edison had expected it might work in theory but was genuinely startled when the device reproduced intelligible speech on the very first attempt. The invention emerged almost accidentally from Edison's work on two other technologies: the telegraph and the telephone. While trying to develop a machine that could transcribe telegraph messages automatically, Edison noticed that the sound of the tape running at high speed resembled spoken words. He began experimenting with the idea that sound vibrations could be physically recorded and replayed. His sketch of the device, handed to his machinist John Kruesi, took roughly 30 hours to build at a cost of about eighteen dollars. The machine operated on a beautifully simple principle. Speaking into a diaphragm caused a needle to vibrate, etching grooves of varying depth into tinfoil wrapped around a rotating cylinder. A second needle, tracing those grooves, recreated the vibrations through another diaphragm. The fidelity was crude and the tinfoil wore out after a few playbacks, but the concept was proven. Sound could be captured, stored, and reproduced at will. Scientific American called it "the most wonderful invention of the age." Edison demonstrated the phonograph at the White House for President Rutherford B. Hayes, who stayed up past midnight listening. Edison himself initially imagined it as a business dictation tool, listing ten potential uses without mentioning music. The music industry, worth hundreds of billions today, was born from a technology its creator considered a glorified answering machine.