Of all his many inventions, Edison held a special fondness for his phonograph. He claimed to have spent 20 hours a day, seven days a week tinkering with the machine in an attempt to properly record the word "species" [source: Dwyer]. And while he might have been exaggerating a bit, we do know that he ended up spending 52 years working to perfect the machine [source: National Park Service].
Nothing can quite replicate the experience of seeing your favorite band perform live. Not so long ago, live performances were the only way to experience music at all. Thomas Edison changed this forever when, working on a method to transcribe telegraph messages, he got the idea for the phonograph. The idea was simple but brilliant: A recording needle would press grooves corresponding to sound waves from music or speech into a rotating cylinder coated with tin, and another needle would trace those grooves to reproduce the source audio.
Unlike Babbage and his decades-long endeavor to see his designs constructed, Edison got his mechanic, John Kruesi, to build the machine and reportedly had a working prototype in his hands only 30 hours later [source: Library of Congress]. But Edison was far from finished with his new creation. His early tin-coated cylinders could only be played a handful of times before they were destroyed, so he ultimately replaced the tin with wax. By this time, Edison's phonograph wasn't the only player on the market, and over time, people began to abandon Edison's cylinders in favor of records, but the basic mechanism remained intact and is still in use today. Not bad for an accidental invention.