UK Singles Chart

The UK Singles Chart (currently entitled Official Singles Chart) is compiled by the Official Charts Company (OCC), on behalf of the British record industry, listing the top-selling singles in the United Kingdom, based upon physical sales, paid-for downloads and streaming. To be eligible for the chart, a single is currently defined by the Official Charts Company (OCC) as either a 'single bundle' having no more than four tracks and not lasting longer than 25 minutes or one digital audio track not longer than 15 minutes with a minimum sale price of 40 pence. The rules have changed many times as technology has developed, the most notable being the inclusion of digital downloads in 2004 and streaming in 2014.

The full chart is a Top 200, though the OCC website contains the Top 100 only. Some media outlets only list the Top 40 (such as the BBC) or the Top 75 (such as Music Week magazine) of this list. Around 6,500 British retail outlets contribute sales data, as well as most UK online digital-download stores. Unlike charts in the United States, no airplay statistics are used for the official UK Singles Chart. The chart week runs from 00:01 Friday to midnight Thursday, with most UK physical and digital singles being released on Fridays. From 3 August 1969 until 5 July 2015, the chart week ran from 00:01 Sunday to midnight Saturday.

Top 40

Top 40 is a music industry shorthand for the currently most-popular songs in a particular genre. When used without qualification it refers to the best-selling or most frequently broadcast popular music. The term is derived from record music charts, a few of which traditionally consist of a total of 40 songs. Top 40 is also an alternative term for the radio format of such music, also known as Contemporary hit radio.

History

The term "Top 40" for a radio format appeared in 1960. The Top 40, whether surveyed by a radio station or a publication, was a list of songs that shared only the common characteristic of being newly released. Its introduction coincided with a transition from the old ten-inch shellac 78 rpm record format for single "pop" recordings to the seven-inch vinyl 45 rpm format, introduced in 1949, which was outselling it by 1954 and soon replaced it completely. The Top 40 thereafter became a survey of the popularity of 45 rpm singles and their airplay on the radio. Some nationally syndicated radio shows, like American Top 40, featured a countdown of the forty highest ranked songs on a particular music or entertainment publication. Although such publications often listed more than 40 charted hits, such as the Billboard Hot 100, time constraints allowed for the airing of only forty songs; hence, the term "top 40" gradually became part of the vernacular associated with popular music.