Hit single

A hit single is a recorded song or instrumental released as a single that has become very popular. Though it sometimes means any widely played or big-selling song, the term "hit" usually refers to a single that has appeared in an official music chart through repeated radio airplay or significant commercial sales.

Historically, before the dominance of recorded music, commercial sheet music sales of individual songs were similarly promoted and tracked as singles and albums are now. For example, in 1894, Edward B. Marks and Joe Stern released The Little Lost Child, which sold more than a million copies nationwide, based mainly on its success as an illustrated song, analogous to today's music videos.

In the United States and the United Kingdom, a single is usually considered a hit when it reaches the official Billboard Magazine’s Hot 100 or the Top 75 of the 'UK Singles Chart' and stays there for at least one week. The Guinness Book of British Hit Singles has used this definition since the 1970s. Some argue that reaching at least the top 100—since the Official Charts Company increased the chart size on their website on 23 June 2007—lets a single be considered a hit due to the increasing singles market after chart rules included download singles.

A hit single is variously called a number one hit, a top 10 hit, a top 20 hit or a top 40 hit, depending on its peak position. In the UK (where radio play is not included in the official charts), this doesn't completely reflect the song's popularity—as the weekly chart position is based solely on direct comparison with concurrent sales of other singles. It is, therefore, not uncommon that a single fails to chart, but has actually sold more copies than other singles regarded as hits based on their higher chart placement in a period of low sales. (This is also possible in the United States, or anywhere, with slow but steady sellers; a number of minor hits, especially those that are popular in specific genera, have earned gold certifications despite relatively poor pop chart performances.)

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