Via Engadget

Ottens started work on the cassette tape in the early 1960s. The way NPR tells the story, he wanted to develop a way for people to listen to music that was affordable and accessible in the way that large reel-to-reel tapes at the time were not. So he first created a wooden prototype that could fit in his pocket to help guide the project. He also worked to convince Philips to license his invention to other manufacturers for free. Philips went on to introduce the first “compact cassette” in 1963, and the rest, as they say, is history. But that wasn’t the end of Ottens’ career. He went on to help Philips and Sony develop the compact disc.