On July 1, 1979, a clunky blue-and-silver electronic gadget went on sale in Japan. The Sony TPS-L2 was not the product of well-thought-out corporate strategy: the most popular story has Akio Morita, the company’s legendary co-chairman, asking the engineer who’d come up with home video, Nobutoshi

Kihara, to design something that would allow Morita to listen to opera on his frequent trans-continental flights. What Kihara designed, the marketing division named the “Walkman”. Sony had had some success popularising miniaturised radios; but still, the revolution that the TPS-L2 would spark was completely unexpected. In a few short years they were ubiquitous: nothing says the ’80s like

big hair, baggy pants and Michael Jackson on your Walkman.

It may be impossible, a mere 30 years later, to understand how that metal box represented a landmark in usability. A vivid example: the BBC handed the original Walkman to a 13-year-old boy, and asked him to use it for a week and record how he felt. Naturally, he was laughed at a bit; but he seemed to view it, further, as shockingly inconvenient (it doesn’t have a “shuffle” mode for songs) and as truly arcane technology (it took him three days to realise you have to turn cassettes over.) But, in the end, the Walkman’s primary innovation is still the one that far more user-friendly MP3 players still offer: a private bubble of music, a soundtrack to your life. It changed public spaces and concepts of privacy for ever.

The portable cassette player might be dead. And Sony lost personal music to the iPod because it didn’t embrace the open-source MP3 format. But the Walkman might be revived as open-source messiah: Sony’s tying up with Google to give Walkmans the Internet and open-source programming. It’s still a powerful brand: PC World recently called it the greatest tech gadget in history. It might be too soon to assume that it’s dead at 30.