<P> Halftime shows are a tradition during American football games at all levels of competition . Entertainment during the Super Bowl, the annual championship game of the National Football League (NFL), represents a fundamental link to pop culture, which helps broaden the television audience and nationwide interest . As the Super Bowl itself is typically the most - watched event on television in the United States annually, the halftime show has been equally - viewed in recent years: the halftime show of Super Bowl XLIX featuring Katy Perry was viewed by 118.5 million, as part of an overall telecast that peaked at 120.3 million at its conclusion--the most - watched television broadcast in U.S. history . The NFL claims that the Super Bowl LI halftime show, with Lady Gaga was the "most - watched musical event of all - time," citing a figure of 150 million viewers based on the television audience, as well as unique viewership of video postings of the halftime show on the league's platforms, and social media interactions (a metric that was never calculated prior to 2017). However, the show was seen by 117.5 million television viewers, making it the second - highest - rated halftime show . </P> <P> Prior to the early 1990s, the halftime show was based around a theme, and featured university marching bands (the Grambling State University Marching Band has performed at the most Super Bowl halftime shows, featuring in six shows including at least one per decade from the 1960s to the 1990s), drill teams, and other performance ensembles such as Up with People . Beginning in 1991, the halftime show began to feature pop music acts such as New Kids on the Block and Gloria Estefan . In an effort to boost the prominence of the halftime show to increase viewer interest, Super Bowl XXVII featured a headlining performance by Michael Jackson . After Super Bowl XXXVIII, whose halftime show featured an incident where Justin Timberlake exposed one of Janet Jackson's breasts, the halftime show began to feature classic rock acts until the return of headlining pop musicians in 2011 . </P>

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