30 years ago there was no iPod, it was all about the Walkman. The mobile music device that seemed to eat a set of batteries each time you played an entire cassette. One had to travel with a horde of batteries plus all those cassettes. Younger generations have no idea how we “suffered” to bring our music alone.
Today I found this article about how you could “Rock and Roll while you stroll” in a 1963 issue of Popular Mechanics. This device made it possible to walk down the street playing your 45’s. It never seems to have caught on. The price back then was $79.95. That is about $570 in 2011 dollars.