Steve Jobs may have wanted you to think that the iPod launched the Mobile Music Revolution, but it was just a new-and-improved mobile MP3 player which replaced the portable CD player which replaced the portable cassette player which replaced the portable 8-track player which replaced the portable radio.

And guess what made radios portable — the transistor. Before transistors, invented in 1947, revolutionized computing for the masses, these semiconductor devices used to amplify and switch electronic signals and electrical power, revolutionized the portable music industry with the transistor radio that was announced by Texas Instruments 60 years ago today. Before the transistor radio, the average small vacuum tube radio weighed about 20 pounds or so and didn’t fit in a pocket, whereas a small transistor radio weighed less than a pound and fit in a (large) pocket.

And those who were Young at Heart could take music with them wherever they went.