a much longer uninterrupted listening time. By the late 1950s, Garrard (of Britain) and Dual (Germany) dominated the high-end record changer market in the United States. From the late 1950s through the late 1960s, VM Corporation (Voice of Music) of Benton Harbor, Michigan, US, dominated the lower-priced original equipment manufacturer (OEM) American record changer market. Most VM record changers were sold to OEM audio manufacturers such as Zenith and installed in console-sized, portable or compact low- to mid-priced stereo or mono systems. VM record changers sold to OEMs were not labeled with the Voice of Music trademark on the unit itself; only those retailed by VM Corporation, either as separate components or integral parts of VM phonographs, were labeled with the VM (Voice of Music) trademark on the changer. Outside the US, VM record-changer technology was licensed to several manufacturers. Telefunken, of then West Germany, was one such company to sign a licensing agreement with VM Corporation. By the mid to late 1960s, a British company BSR–MacDonald displaced VM as the world largest record-changer manufacturer and dominated the OEM changer market in the US as well. Garrard, in 1960, introduced a high fidelity record changer with a professional grade balanced tonearm and heavy cast non-magnetic platter, both features previously found only on manual turntables. To distinguish it by its superior performance, it was called an "automatic turntable." The name, and the improved performance, caught on and other manufacturers began producing automatic turntables with professional-grade features and performance. Most mid-priced consumer record players of the 1950s through the 1970s were equipped with changers, but they started to decline in popularity as cassettes and compact discs replaced vinyl records in the 1980s and 1990s. Record-stacking changers eventually became rarer due to the gradually growing belief that they contributed greatly to record wear and "warping," and were eventually superseded by manual turntables which served as separate parts of component systems or were integrated into compact systems that played one record at a time and were felt by some to save record wear by gentler treatment during play. Operation Record-changer mechanisms were sometimes complicated. They typically held a stack of records on an extended central spindle supported by an arm (separate from the tonearm housing the cartridge and stylus which played the records). Some units had feelers that could detect the size of each record (the three standard sizes being 7, 10 or 12