Other companies watched from the sidelines as buyers stayed away from Nakamichi's new design. To millions of consumers, the search for higher and higher fidelity meant that an extra-slow tape speed was a step backward. Other manufacturers even thumbed their noses at Nakamichi by selling cassette decks that recorded at double speed, but those designs, too, ended up as failures. You would think that this would have ended the odd experiments with even-longer playback techniques, but there was one more try. Monaural sound needs only one track, since it does not use left and right signals.
All CDs have two tracks, one each for left and right.
So that's just what this company did. Old monaural recordings were reissued on CDs, with separate performances on each of the two tracks. You listened to these oddball CDs by turning your balance control all the way in one direction or the other. But consumers didn't think so. And once again, the other companies stood back, chuckled a bit and kept making money and CDs the regular way.