The Sony Walkman TPS-L2 dropped on July 1, 1979, and it straight-up changed how people listened to music. Before this, “portable” music meant lugging around a boombox, but the TPS-L2 was a sleek cassette player you could clip to your belt and take anywhere. It had dual headphone jacks so you and a friend could listen together, plus that iconic “Hotline” button that let you talk without taking your headphones off. Sony quickly followed with upgrades like the WM-2 in 1981 and the slimmer WM-10 in 1983, making the Walkman a must-have accessory through the ’80s and into the ’90s. This little blue-and-silver box didn’t just play music—it kicked off the entire personal audio revolution.