itself as a pillar of the community and placed emphasis on general full-service programs. In 1941, with the implementation of the North American Regional Broadcasting Agreement (NARBA), WLAC moved to a "Clear Channel" assignment of 1510 kHz, and received permission to increase its power to 50,000 watts. WLAC thus became the second clear-channel station in Tennessee, after WSM. While WSM was a Class I-A station, using a non-directional antenna at all times, WLAC shared its clear channel assignment with KGA in Spokane, Washington. Since WLAC and KGA were designated as co-equal Class I-B stations, both were required to use a directional antenna at night to mutually protect each other's signals. KGA has since given up its clear-channel status, but WLAC is still required to conform its nighttime signal. Even with this restriction, it reaches parts of 28 states and three Canadian provinces at night. Even at 50,000 watts, WLAC provides only secondary coverage of several inner-ring suburbs, such as Murfreesboro; the simulcasts on HD Radio serve in part to alleviate this shortfall. Late night rhythm and blues In the 1950s, 1960s and 1970s, WLAC was legendary for its quartet of nighttime rhythm and blues shows hosted by Gene Nobles, "John R." (John Richbourg), Herman Grizzard, and Bill "Hossman" (or simply "Hoss") Allen. Thanks to the station's clear channel designation, the signal reached most of the Northeast and Midwestern United States. WLAC described itself as the nighttime station for half the nation with African-American listeners, especially in the Deep South as the intended audience of the programs. Further, several foreign countries, particularly islands in the Caribbean and southern Canada, were within range of the station's nighttime signal; the music heard on WLAC played a notable role in the development of ska music as a result. WLAC was also popular with some young white teenagers. Radio historians believe that the nightly "Rhythm and blues" WLAC shows, in part, laid the foundational audience for the rock and roll phenomenon that began in the late 1950s. Nobles began the move, in 1946, to play what were considered at the time "race" records, a euphemism intended to deter supposedly respectable audiences. But he and the others reached large numbers of African-American listeners in places like the Mississippi Delta, the Carolina Lowcountry, Louisiana, Chicago, and Detroit, people whom practically no other radio stations were serving. Gradually phasing in artists like Amos Milburn, Chuck Berry, and Fats