Karlheinz Brandenburg was finishing up his doctorate in computing when his advisor suggested a research topic: how to transfer data over digital phone lines, a process thought impossible at the time. Impossible it was, but only for another four years, when more powerful computers enabled work to begin on compressing audio signals into layers, which could then be saved or discarded depending on their significance. Brandenburg formed the Motion Picture Experts Group to develop a world standard for this compression: as the name implies, their goal was to transfer video to CD-Rom, but their legacy would be something considerably different.

On this day, July 14, in 1995, the MPEG layer 3 audio file was born, with the group deciding to append to it the extension “.mp3”. They envisioned the Internet as the medium for their invention’s spread; they just did not realize how fast.

Two years after its debut the MP3 file hit the tipping point. As long as mp3 encoders were expensive, the amount of music in that format was limited. But then an Australian hacker using a stolen Taiwanese credit card bought a German encoding software program, reverse-engineered it, figuring out how to make MP3 files, and uploaded the result along with detailed instruction free of charge onto a university FTP site. From there the wildfire spread of MP3 could no longer be contained.