"OMG" is a song by American recording artist Usher and American rapper will.i.am, who also wrote and produced the song. It uses the auto-tune effect in several lines, as well as Jock Jams-esque sports arena chanting. It was released on March 22, 2010 as the first worldwide single off his sixth studio album, Raymond v. Raymond, and the fourth single overall, following the three US singles "Papers", "Hey Daddy (Daddy's Home)", and "Lil Freak". The song was met with a mixed reception from critics, who criticized the use of auto-tune, but commended the song's dance and club vibe. The song marks the second time that Usher has collaborated with will.i.am, following the single "What's Your Name", from his previous album Here I Stand (2008).

"OMG" topped the charts in Australia, Ireland, New Zealand, the United Kingdom and the United States. The song became his ninth number-one hit in the United States, making him the first 2010s artist to collect number-one singles in three consecutive decades. He became only the fourth artist of all-time to achieve that feat. Usher also became the third artist to have at least one number-one song from five consecutive studio albums. The song's choreography and dance-heavy accompanying music video has been compared by critics to that of "Yeah!". Usher performed the song live several times including on the ninth season of American Idol with will.i.am. He also performed the song as a part of a medley during his critically acclaimed performance at the 2010 MTV Video Music Awards. "OMG", was named the fifth best selling song of 2010 in the US, selling 3.8 million units. The song sold 6.9 million copies worldwide during that year.

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