sentences:  Licensed to Peotone, Illinois and currently serving Chicago, it first began broadcasting in Zeeland, Michigan in 1990 under the WBMX call sign, serving Muskegon and Grand Rapids.The station has since been through a number of different formats and call signs, and changed market areas, which is rare for a station.640 kilohertz is a United States clear-channel frequency, on which KFI in Los Angeles and KYUK in Bethel, Alaska are the dominant Class A stations.