The casette, developed by Philips electrical manufacturer, has advantages over cartridges. New about cassettes is their use as a vehicle for commercially recorded music.

When the technique of tape recording was developed a quarter-century ago, it unreeled a whole new way of marketing recorded music. The best tapes had all the high fidelity of phonograph disks but none of their low resistance to wear and tear. The trouble was that they were cumbersome: wound…