Although The Walkman was released 40 years ago, Sony had actually made something that will look familiar another 10 years earlier and was used on Apollo moon missions: https://airandspace.si.edu/multimedia-gallery/5254hjpg https://www.sony.net/Fun/design/history/product/1960/tc-50.h...

Incidentally, I only discovered this recently after hearing the Apollo 11 astronauts use one to play a prank on mission control while on the way back to earth. You can hear this at the amazing https://apolloinrealtime.org/11/ (definitely works best on desktop not mobile)