Christina María Aguilera

• 2006–09: Back to Basics, motherhood and greatest hits album
Aguilera's fifth studio album, Back to Basics was released August 15, 2006. The album debuted at #1 in the US, the UK and eleven other countries. Aguilera described the double CD as "a throwback to the 20s, 30s, and 40s-style jazz, blues, and feel-good soul music, but with a modern twist." The album received generally positive reviews, although many critics commented on the album's length saying, "At one disc, this would have been nothing short of masterful." A review in AllMusic adds, "Back to Basics also makes clear that Stripped was a necessary artistic move for Christina: she needed to get that out of her system in order to create her own style, one that is self-consciously stylized, stylish, and sexy." The critically acclaimed lead single "Ain't No Other Man" was a substantial success, reaching #2 on the World Chart, #6 in the U.S., and #2 in the UK. Producers on the album included DJ Premier, Kwamé, Linda Perry, and Mark Ronson. The follow-up singles did very well in different regions, "Hurt" in Europe and "Candyman" in the Pacific. She co-directed both music videos, the former with Floria Sigismondi who directed her "Fighter" video, and the latter, "Candyman", with director/photographer Matthew Rolston which was inspired by The Andrews Sisters. Back to Basics has sold 4.5 million units worldwide, with over 1.7 million sold in the US.
In late 2006 Aguilera collaborated with Sean "Diddy" Combs on a track, titled "Tell Me", from his album Press Play. She also began the Back to Basics Tour in Europe followed by a 41-date North American tour in early 2007. After this, she toured Asia and Australia, where it was supposed to end on August 3, however she canceled her dates in Melbourne and her final two in Auckland due to an illness. Her extravagant arena tour included cabaret, three-ring circus and juke joint sets and 10 piece costumes designed by Roberto Cavalli. She released her concert DVD Back to Basics: Live and Down Under the following year. The tour grossed nearly 50 million by the end of the year in North America and an additional 40 million worldwide in her Europe and Australia dates, grossing almost 90 million by the end of the tour. It was the most successful US tour by a female in 2007.
At the 49th Grammy Awards, Aguilera again won the Best Female Pop Vocal Performance for "Ain't No Other Man". She made a noteworthy performance at the ceremony paying tribute to James Brown with her rendition of his song "It's a Man's Man's Man's World". In January 2007, she was named the 19th richest woman in entertainment by Forbes, with a net worth of US$60 million. Aguilera performed "Steppin' Out With My Baby" with Tony Bennett on his NBC special Tony Bennett: An American Classic and on Saturday Night Live. They performed at the 59th Primetime Emmy Awards where both specials received Emmys. "Steppin' Out" was nominated for Best Pop Collaboration with Vocals at the 50th Annual Grammy Awards.