Sony brought out its first Walkman, the TPS-L2, in Japan on July 1, 1979. The very first portable audiocassette player allowed its user to privately enjoy music through headphones plugged directly into the unit. This was revolutionary, and it soon won over the world.
Over time, some models would offer double audiojacks, able to play both sides of a cassette tape automatically, and be able to record sound. As such, the WM-D6C and WM-DD9 models would be among the top sellers of the 1980s and are now prized by collectors.