Louis Ottens — the Dutch engineer credited with inventing the audio cassette tape — has died at the age of 94.

Dutch newspaper NRC Handelsblad first reported that Ottens died March 6th in Duizel, the Netherlands. No cause of death was provided.

A longtime engineer at the Dutch electronics and technology company Philips, Ottens — in his role as head of the product development department — led the Belgian team charged with converting the bulky reel-to-reel tape recorders of the era into something more portable and consumer-friendly; Ottens’ goal was to make a cassette tape that could fit a jacket’s inside pocket.

After its development, Philips’ audio cassette made its debut at electronics fairs in August 1963. Soon after, Japanese electronics companies created their own iteration of the audio cassette of varying sizes, but Ottens struck a deal between Sony and Philips to ensure their model would become the patented cassette on the market.

Lou Ottens, Inventor of the Audio Cassette Tape, Dead at 94 – Rolling Stone

Not only the cassette gave us portability but also the ability to finally mix and match music to our liking. He allowed us to have the famous mixed tapes.

I was a TDK guy, but I figure this classic Maxwell commercial is a fitting tribute.