structural:summarization
A record chart, in the music industry, also called a music chart, is a ranking of recorded music according to certain criteria during a given period. Many different criteria are used in worldwide charts, often in combination. These include record sales, the amount of radio airplay, the number of downloads, and the amount of streaming activity. Some charts are specific to a particular musical genre and most to a particular geographical location. The most common period covered by a chart is one week with the chart being printed or broadcast at the end of this time. Summary charts for years and decades are then calculated from their component weekly charts. Component charts have become an increasingly important way to measure the commercial success of individual songs. A common format of radio and television programmes is to run down a music chart.