On this day three decades ago, Sony's original blue-and-silver Walkman went on sale in Japan, launching an era of personal, portable music and generations of oblivious subway riders and pedestrians.

The first Walkman, called the TPS-L2, cost 33,000 yen (roughly $150) in Japan and didn’t make it to the U.S. until 1980. In case you forgot, the original cassette-playing device had some quaint features, including a pair of headphone jacks that allowed two people to listen simultaneously and a "hotline" switch that activated a microphone to pipe in ambient sound instead of music.

For the price of a 1979 Walkman, you can get a Walkman Video MP3 Player today, with four gigabytes of memory that stores up to 40 hours of music and 10 hours of video, capabilities that were inconceivable during the disco era.

The BBC earlier this week crystallized the difference between then and now in a story about a 13-year-old who swapped his iPod for a Walkman for a week. Among the highlights: the teen took three days to figure out there was a flip side to each cassette, he thought the metal/normal switch for tape type was a "genre-specific equaliser," and he managed to create an "impromptu shuffle feature" by holding down the rewind button and releasing it randomly.

Image © Kafziel via WikiMedia Commons