Not Myself Tonight

"Not Myself Tonight" is a song by American singer Christina Aguilera for her sixth studio album Bionic (2010). It was released by RCA Records as the lead single from the album on April 2, 2010. Produced by Jamal Jones a.k.a. Polow da Don and co-written in collaboration with Greg Curtis, Ester Dean and Jason Perry, "Not Myself Tonight" is an electropop, electro-R&B and dance-pop song, which explores Aguilera's adoption of different personas on the dance floor.

"Not Myself Tonight" received mixed reviews from contemporary music critics: some of whom praised the song's musical style, while others criticized its lyrics. Internationally, the song reached Top-5 peaks in Hungary and Japan, while reaching Top-15 in Canada, Scotland, Italy and the United Kingdom. Elsewhere, the song peaked inside the Top-40 in a total of 21 countries, including the United States where it peaked at number 23 on the US Billboard Hot 100. Additionally, the song peaked at number one on the Dance Club Songs chart. The single was certified gold by the Australian Recording Industry Association (ARIA) for shipments exceeding 35,000 copies in Australia.

An accompanying music video for "Not Myself Tonight" was directed by Hype Williams, and was released on April 28, 2010. Serving as an homage to the music video for Madonna's "Express Yourself", the video was S&M-themed. To promote the song, Aguilera performed "Not Myself Tonight" at the 2010 MTV Movie Awards, VH1 Storytellers and The Oprah Winfrey Show, amongst others.