Walkman

Sony Walkman TPS-L2, 1979 The player that made private listening in public normal. It went on sale in Japan on July 1, 1979, for ¥33,000, and cost $200 when it reached the U.S., where buyers in 1980 faced a month-long wait for stock. What makes the first model worth knowing is how sociable Sony assumed it would be. It had two headphone sockets, and an orange "hotline" button faded the tape down so you could talk to the person beside you without taking your headphones off. Its successor, the WM-2, dropped the hotline for a simple mute button on the headphone cord, an early sign of how quickly people embraced listening alone.