X is the tenth studio album by Australian singer Kylie Minogue. It was released on 21 November 2007 by Parlophone. It is her first release since the greatest hits compilation Ultimate Kylie (2004), and her first studio album since Body Language (2003). Work on the album began following Minogue's gradual recovery from breast cancer and subsequent radiotherapy treatment. Her cancer, which was diagnosed in May 2005, resulted in the postponement of Showgirl: The Greatest Hits Tour midway through its run. Minogue resumed the tour in late 2006, in the midst of recording X, and was completed later in the following year. The album introduced new American and European producers including Bloodshy & Avant, Guy Chambers, Calvin Harris and Freemasons.
X has received positive reviews from music commentators. Many critics had commended the production, Minogue's innovative writing and many believed that it was a true welcome back to the pop scene. However, upon release, some critics were divided whether the album was a 'comeback' album and some noted the fillers and theme inconsistency. Commercially, X was a success. In Minogue's native Australia, the album debuted at number one on the Australian Albums Chart, becoming her first number-one album since Body Language (2003) and was certified platinum by the Australian Recording Industry Association (ARIA). In the United Kingdom, the album peaked at number four, being held off by artists Westlife, Shayne Ward (which was the highest debuting album that week) and Leona Lewis. It gained a higher position than her last record and was certified Platinum by the British Phonographic Industry. The album achieved strong charting internationally, peaking inside the top 20 in countries including Austria, Germany, Ireland, Taiwan and France.
"2 Hearts" was released as the lead single from X. The song received mixed reviews, praising the lazy tone and production while criticizing the lack of commercial appeal and memorability. The song was a commercial success, peaking inside the top 10 in countries including Australia and Spain (peaking at number one in both territories), Italy, Ukraine, Sweden and the United Kingdom. Two singles were released on 16 and 17 February, respectively; "Wow" was released in Australia, Europe and the United States, while "In My Arms" was released in Europe. The first was positively received and achieved chart success, while the latter did not have the similar chart progression. "All I See" and "The One" were released as digital singles, the first to promote the album in the United States and the latter released in Europe.
X was promoted by the KylieX2008 where she traveled around Europe, Oceania, South America, Asia and South Africa. The tour received favorable reviews from critics and was a commercial success, making it Minogue's most expensive tour at the time. Due to Minogue's lack of success in North America, she traveled there in 2009 for her tour For You, for Me to promote the album. The album was nominated for a BRIT Award for International Album in 2008, as well as a Grammy Award for Best Electronic/Dance Album in 2009, Minogue's fifth Grammy Award nomination. According to The Times, the album had sold one million copies worldwide as of December 2008.