The MP3 turns 25: A weird filename extension turned music revolution

Karlheinz Brandenburg, head of the Fraunhofer Working Group for Electronic Media Technology Ilmenau, developed the audio file format that turned the entire music industry upside down. — Heinz Hirndorf/dpa

MPEG Layer 1 has long been forgotten. MPEG Layer 2 can sometimes still be found in old TV sets. But it was MPEG Layer 3, better known as the MP3, that spurred a revolution in music.

It started 25 years ago in July 1995, when a team of researchers in Germany found a way to compress audio data into a smaller file that was easier to share online.