Enlarge (credit: airplaneengine) The 8-track cartridge, aka the Stereo 8, first appeared at trade shows in 1964, just 18 months after the cassette, and it did initially seem to have it all: it was comparatively small, portable, and had pretty good audio quality. And despite its roots in the Mad Men in-car market of the 1950s, it was seemingly future-proof, too, with a unique potential for quadraphonic sound (a potential later realised, in part).