In 2011, nine acts achieved their first US number-one single, either as a lead artist or a featured guest: Wiz Khalifa, Adele, Pitbull, Afrojack, Nayer, LMFAO, Lauren Bennett, GoonRock and Calvin Harris. Six collaboration singles topped the chart. Pop singers Adele, Britney Spears, Katy Perry and Rihanna each earned two number-one songs during the year.
