在此前专辑《Viva la Vida》中没有发表过的八首作品，被Coldplay做成一张名为《Prospekt’s March》的新EP。 这是双EP中的《Lost!》。LOST单曲的不同版本，包括Jay-Z混音新版本及Chicago现场！ "Lost!" is a song by the British alternative rock band Coldplay. The band co-produced it with Brian Eno and Markus Dravs for their fourth album, Viva la Vida or Death and All His Friends. Several official versions of the song exist, including vocalist Chris Martin's separate recording with a piano accompaniment (known as "Lost?") which appears as a B-side for "Violet Hill", and a version that features American rapper Jay-Z (known as "Lost+") which appears on their 2008 EP Prospekt's March. Although it didn't match the commercial success of the album's previous singles, the song was released on 10 November 2008 as the third official single (fourth overall) off the album to generally positive critical reviews. A live version was released viadigital download following a performance of the band and Jay-Z at the 2009 Grammy Awards, spurring high digital sales and giving "Lost!" a new peak at number 40 in the United States. In the United Kingdom, it peaked at number 54 due to no physical release. The accompanying music video to the single features a live performance of the band in the United States. Coldplay launched a contest through their website, in which fans submitted self-made music videos. The winning entries were posted on the band's website.