Remember the compact audio cassette tape? It was in some ways the gnarliest of all 1970s/1980s media formats, derided for its high levels of hiss, wow and flutter and the relative fragility of the tape inside, but simultaneously prized for its portability — the cassette tape was the format of choice for listening to music in your car and in your pocket. For the 40th anniversary of the original Walkman, Sony takes a trip back in time through physical media formats, including tape, CD, MiniDisc, and Memory Stick (the common SD card supported by current-generation Walkman units is absent from the parade), by showcasing the history of its Walkman device design.