Amazon.com description: Product Description: Radio station WLS was a leading music tastemaker during the 1960s. During night-time hours, its AM signal could be received clearly from Canada to northern Mexico. In addition to a brief history of the station, this volume compiles the weekly Top 40 chart listing distributed free at record retailer outlets and via mail (upon request). Like the other radio charts titles, my goal was to provide a convenient chronological compilation of weekly surveys with corrections of the considerable errors found in both the original sources and in translation to online sites. These radio charts – which exist in the public domain – can be found in a multitude of sources, including original published sheets distributed via retail outlets, mail inquiries, etc., notation of on-air broadcasts, back issues of area newspapers (where stations are located) and music trade periodicals, specialized reference books, and websites interested in historical documentation, most notably, Oldiesloon, musicradio77, and ARSA. I employed multiple sources in the compilation of each radio chart volume in order to provide the most accurate data possible.