LOS ANGELES -- There is a tear in the beer of country music fans here. After more than 20 years on the air, the city's only country music station, KZLA-FM, abruptly left the air Thursday and was seamlessly replaced with the rhythmic pop of "Movin' 93.9," which plays artists such as Beyonce, Janet Jackson and Jennifer Lopez. KZLA's sudden and unannounced demise leaves America's two most populous cities, Los Angeles and New York, without country music stations. In Los Angeles, longtime country fans and station employees wondered at the logic of ending country radio in their city, which ranks in...