Would that be the new matchbox-sized digital audio library device? Actually, I'm thinking of the first ever personal stereo, which played an audio cassette - if you can remember those.
Cassettes, they're so beyond 'old school', man. Be that as it may, the Walkman revolutionised the way many people listen to music, allowing them to do it on the move.
When? 1979.
Who? Kozo Ohsone, Masaru Ibuka and Akio Morita.
Er, who . . . ? These Sony personnel comprised the general manager of the Japanese electronics giant's tape-recorder business division, co-founder/chief adviser and co-founder/chairman respectively.
Did the public go for the invention immediately? You betcha! Within two months the initial batch of 30,000 had been snapped up by those keen to add such hi-tech wizardry to their collection of cutting-edge accessories to flaunt: multi-functional calculators and digital watches. Two years later, 1.2 million units of the TPS-L2 had been sold globally.