The Walkman is 40.
Monday marked the 40th anniversary of Sony's portable music device that changed the way many people listened to music. The first Walkman used cassette tapes before evolving into CDs, ruling the roost for the better part of 20 years since it was introduced in 1979.
Apple's iPod stole a lot of the Walkman's thunder when it came out in 2001, but the Walkman also eventually moved into MP3 territory. It never quite caught up.
The MP3 version of the Walkman is still available in stores.
Happy Birthday Walkman