Stewart Wolpin

Forty years ago today Sony introduced a portable cassette player that would forever change the way the world experienced music on-the-go.

You may be excused if you thought that Apple's AirPods are the first and only so-called "true wireless" earphones—completely cordless in-ear "buds" that connect both with each other and to your smartphone via Bluetooth—since their distinctive white sticks seem to be protruding from hipster ears everywhere.

Fortunately, if you're not an iPhone owner, or a fan of the AirPods' distinctive look or not-necessarily one-size-fits-all fit, there is a growing number of other "true wireless" earbud choices. And in contrast with Apple's one-for-all approach, most AirPod alternatives address specific use cases, style preferences, and budgets.

A momentous occasion in the evolution of recorded music occurred 20 years ago when a California district court ruled to allow the sale of a curious new portable music player in the face of opposition from the Recording Industry Association of America (RIAA). Here’s a compressed history of the events surrounding the birth of the MP3 player.