In da Club

Dre and Mike Elizondo made the track about six months before release, and it was first offered to D12 for the 8 Mile soundtrack, who passed, and then to Rakim, whose version was never released. 50 Cent wrote the lyrics in around an hour. Much of the album was dark, so he wanted something that was the exact opposite, and he called the song a celebration of life, since every day is someone's birthday. Sha Money XL said he built the chorus from a Lloyd Banks line about a bottle full of Bubb. He first recorded the drum beat alone in Sha Money's basement in Long Island, then re-recorded it two weeks later in Los Angeles, where Dre and Elizondo added synths and an eight-note guitar part. Elizondo said Dre's idea was less is more, but make it as big as possible.

Released as a digital download on 7 January 2003, it entered the Hot 100 at 67 and topped the chart after eight weeks, his first number one. It stayed there nine consecutive weeks, and in March 2003 broke a Billboard record as the most listened-to song in radio history within a week. Billboard ranked it the number-one song of 2003, and the RIAA certified it diamond in 2023. It reached number three in the UK and number one in Australia. Philip Atwell directed the video in December 2002, set in a fictional Shady/Aftermath Artist Development Center, with Eminem and Dre in lab uniforms. It won best rap video and best new artist at the 2003 MTV Video Music Awards. The song was nominated for best male rap solo performance and best rap song at the Grammys and lost to Eminem's Lose Yourself.

In January 2006 a former 2 Live Crew manager sued for copyright infringement over the phrase it's your birthday. The suit was dismissed by a US district judge, who ruled that the phrase was a "common, unoriginal and noncopyrightable element of the song". Beyonce recorded a version, Sexy Lil Thug, over the instrumental, and the original has been sampled or interpolated in at least 90 songs, among them Kanye West's Good Life. 50 Cent performed it in the Super Bowl LVI halftime show on 13 February 2022.