William Powell Lear, the man behind LearJet, was also the inventor of the 8-track cartridge tape system. During the early 1960s, a number of shell-encased continuous-loop audiotape systems coexisted. Lear's 8-track was by no means the first such system, in fact, the Lear cartridge is in most respects identical to the 4-track tape which came before it. The main mechanical difference between the two systems is that in a 4-track, the pinch roller is part of the player, whereas in an 8-track, the pinch roller is part of the tape cartridge.

This refinement was probably intended to reduce tape tangling (and any tracker can tell you how well that works), as well as to help Lear secure a patent for his invention. Another difference between them is that 4-track divided the tape itself into four channels (tracks), comprising two stereo programs. This restricted the total playing time to something like 40 minutes, because of the limited length of tape which could be contained within a cartridge. Lear divided the tape into eight channels (tracks).

While this doubled the potential playing time of the cartridge, it also created a new problem. Both systems involve a tape head which repositions itself along the width of the tape in order to change programs. This means that the slightest misalignment of the tape head (or for that matter of the tape itself within the cartridge) in an 8-track system means that you hear shadows of other tracks bleeding into the program which is playing. A 4-track, with its wider channels, is more forgiving of misalignment.

While some of Lear's improvements over 4-track are a bit dubious, his real refinements were in the area of marketing. All 1966 Fords offered a factory installed in-dash 8-track player. In the 1967 model year, Chrysler and GM offered the same. By the late 1960s, several companies were making players for the other tape loop systems, including 4-track, but the only serious competition came from cassette tapes (which appeared at around the same time as 8-tracks) and the almighty vinyl records.

Eight-track tapes were with us for quite a long time. 8-track was the preeminent portable and car audio format of the 1970s. Record clubs like Columbia House offered 8-track tapes well into the 1980s (Madonna's early albums, for example, as well as Michael Jackson's "Thriller," were offered to club members on 8-track). Although there are reports that brand-new tapes are still coming out of Nashville with truckers as the intended audience, these sightings have not been confirmed.