bulated, with the chart titled "Most Played Juke Box Folk Records". For approximately ten years, from 1948 to 1958, Billboard used three charts to measure the popularity of a given song. In addition to the jukebox chart, these charts included: The "best sellers" chart – started 15 May 1948, as "Best Selling Retail Folk Records". An airplay chart – started 10 December 1949, as "Country & Western Records Most Played By Folk Disk Jockeys". The juke box chart was discontinued in June 1957. Starting with the 20 October 1958, issue, Billboard began combining sales and radio airplay in figuring a song's overall popularity, counting them in one single chart called "Hot C&W Sides". The chart was published under the title Hot C&W Sides through the 27 October 1962, issue and "Hot Country Singles" thereafter, a title it would retain until 1990. On 20 January 1990, the Hot Country Singles chart was reduced from 100 to 75 positions and began to be compiled entirely from information provided by Nielsen Broadcast Data Systems, a system which electronically monitors radio airplay of songs. Four weeks later, on February 17, the chart was retitled "Hot Country Singles & Tracks". Beginning with the January 13, 2001, issue, the chart was reduced from 75 to 60 positions, and all songs on the chart at the time had their tally of weeks spent on the chart adju