Title: Super Bowl 50 halftime show
Content:   Coldplay, Rihanna, and Katy Perry were considered as potential acts for the Super Bowl XLIX halftime show in 2015. Perry was soon confirmed as the headliner of the halftime show in November 2014. In summer 2015, many acts were being rumored as potential headliners for the 2016 halftime show including Taylor Swift, Britney Spears and One Direction. In September 2015, it was reported that Bruno Mars was set to curate the Super Bowl 50 halftime show, but the next month in October, It was reported that Maroon 5 was in talks to headline, but the band said they haven't had any conversations with the NFL about headlining, but were open to it. Maroon 5 would eventually headline Super Bowl LIII's halftime show. In late November 2015, reports 
Title: Super Bowl 50 halftime show
Content:  The Super Bowl 50 Halftime Show took place on February 7, 2016, at Levi's Stadium in Santa Clara, California as part of Super Bowl 50. It was headlined by the British rock group Coldplay with special guest performers Beyoncé and Bruno Mars, who previously had headlined the Super Bowl XLVII and Super Bowl XLVIII halftime shows, respectively. The show received mixed reviews, attracting 115.5 million viewers.
Title: Super Bowl 50
Content:   In late November 2015, reports surfaced stating that "multiple acts" would perform during the halftime show. On December 3, the league confirmed that the show would be headlined by the British rock band Coldplay. On January 7, 2016, Pepsi confirmed to the Associated Press that Beyoncé, who headlined the Super Bowl XLVII halftime show and collaborated with Coldplay on the single "Hymn for the Weekend" (which was removed from the setlist before the game), would be making an appearance. Bruno Mars, who headlined the Super Bowl XLVIII halftime show, and Mark Ronson (Mars's collaborator on "Uptown Funk") also performed.
Title: Super Bowl 50 halftime show
Content:  a snippet of "Clocks" transitioning into "Fix You," and Martin sang along to some of the songs included in a video montage of past Super Bowl halftime and national anthem performances, containing show numbers by Bruce Springsteen, Missy Elliott, Katy Perry, The Rolling Stones, Paul McCartney, Stevie Wonder, Diana Ross, James Brown, Whitney Houston, Michael Jackson, The Black Eyed Peas, U2, Prince, Beyoncé, and Mars. The show concluded with the band performing "Up&Up" with Beyoncé, Mars, and everyone taking part in the show. At the end of the performance, the audience participated in a card-stunt creating a rainbow and the phrase, "Believe in love", the closing lyrics to Coldplay's A Head Full of Dreams.
Title: Super Bowl LIII halftime show
Content:  As early as September 2018, multiple sources had reported that Maroon 5 were to headline the Super Bowl LIII halftime show, but the NFL had not yet made an official announcement. In October 2018, it was reported that Pink and Rihanna had each declined an offer to headline, the former because the negotiation process was too lengthy for her taste and the latter due to her support of Colin Kaepernick. In December, Billboard reported that Houston-based rapper Travis Scott was expected to make a guest appearance. On January 13, 2019, the NFL officially announced that Maroon 5 would headline the show, joined by Scott and Big Boi, an Atlanta native and member of the hip-hop duo Outkast. In an interview, Maroon 5 lead singer Adam Levine explained that the band wanted to bring the halftime show "back to a time when it was a 
Title: Super Bowl LIII halftime show
Content:  The Super Bowl LIII Halftime Show, officially known as the Pepsi Super Bowl LIII Halftime Show, took place on February 3, 2019 at Mercedes-Benz Stadium in Atlanta, Georgia, as part of Super Bowl LIII. It was headlined by American pop group Maroon 5, joined by rappers Big Boi and Travis Scott as guests. Prior to the show, it was reported several musicians turned down offers to perform the show due to their support for Colin Kaepernick, who has accused the NFL and its franchises of colluding against him for his national anthem protests against police brutality. As such, Maroon 5, Big Boi, and Scott, along with national anthem singer Gladys Knight, were criticized by fans and critics for accepting the invitation. In response to the controversy, Scott only agreed to participate if the NFL made a donation 
Title: Super Bowl 50 halftime show
Content:  stating that multiple acts would perform during the halftime show. Coldplay was confirmed as the lead half time performer for Super Bowl 50 on December 3, 2015, one day before the release of their seventh studio album A Head Full of Dreams. It was later confirmed that Beyoncé and Bruno Mars would join Coldplay as special guests. When Chris Martin originally called Mars to ask him to perform with Coldplay, Mars was wary of a multi-artist performance. The singer of Coldplay then invited Mars to his studio in Malibu where he was working. There, Martin revealed to Mars that he wanted for him to perform "Uptown Funk" with Beyoncé. Despite this, Mars remained skeptical and asked Martin to talk to Beyoncé to determine how she felt about 
Title: List of Super Bowl halftime shows
Content:   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. Prior to the early 1990s, the halftime show 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. Since 2013, Pepsi has been the official sponsor of the halftime show.
Title: Super Bowl XXII
Content:  The pregame festivities featured a tribute to entertainer Bob Hope, who was approaching the age of 85. Members representing the military service branches marched out onto the field in full dress uniforms, and in unison saluted Bob Hope for his dedication to helping the troops. Trumpeter Herb Alpert performed "The Star-Spangled Banner", while Pro Football Hall of Fame wide receiver Don Hutson participated in the coin toss ceremony (the game happened to coincide with Hutson's 75th birthday). Alpert's performance was the last non-vocal performance of the National Anthem in a Super Bowl to date. The halftime show, produced by Radio City Music Hall, was titled "Something Grand" and featured performances by vocalist Chubby Checker, The Rockettes, and 88 grand pianos. Among the 44 Radio City Music Hall Rockettes, American performer Jennifer Jones made her national debut as its first African American Rockette. Checker's performance marked the first time a major artist performed during the show. This was the final Super Bowl to feature the football-style logo at the 35-yard-line which had been in use since Super Bowl XIV.
Title: Super Bowl XXVII halftime show
Content:  The Super Bowl XXVII halftime show took place on January 31, 1993, at the Rose Bowl, Pasadena, California, as part of Super Bowl XXVII. It featured American singer Michael Jackson. The halftime show was broadcast on NBC. This halftime performance increased the television ratings by a significant amount, and remains one of the most watched events in American television history with 133.4 million viewers. Jackson's performance received worldwide critical acclaim, and has since been hailed as the greatest halftime show of all time. Jackson’s appearance also started the NFL's trend of signing top acts to appear during the Super Bowl to attract more viewers and interest.

Question: who performed the halftime show at super bowl 51?
Answer: Lady Gaga.