The behind-the-scenes tales of hit products and creations from Japan: this is Japan's Top Inventions. This time, the gadget that lets you enjoy music anytime, anywhere with just a pair of headphones: the portable music player. The world's first of these portable players was developed by a Japanese manufacturer in 1979. Listening to music on the go is now a part of daily life around the world. This time, the story of the invention that made it all possible.