Fundamental is the ninth studio album by English synth-pop duo Pet Shop Boys. It was released in May 2006 in the United Kingdom, Europe, Japan, and Canada, and in late June 2006 in the United States. The album entered the UK Albums Chart at number five on 28 May 2006. In the US the album peaked at number 150 on the Billboard 200, selling 7,500 copies in its first week. As of April 2009 it had sold 46,000 copies in the US and 66,000 copies in the UK.