Compatible cartridges for magnetic tapes

Magnetic tape may be offered in cartridge form at a price competitive with phonograph disks. Cartridges of different sizes are designed either for high quality or for maximum tape economy. All of these will operate on present-day machines, as well as on automatic designs. A cartridge changer allows records to be played in sequence. The erase feature offers interesting possibilities for sale of pure music separate from the sale of cartridges.