The Dark Side of the Moon is the eighth studio album by the English progressive rock band Pink Floyd, released on 1 March 1973. It built on ideas explored in the band's earlier recordings and live shows, but lacks the extended instrumental excursions that characterised their work following the departure in 1968 of founder member, principal composer, and lyricist, Syd Barrett. The Dark Side of the Moon explores themes including conflict, greed, the passage of time, and mental illness, the latter partly inspired by Barrett's deteriorating mental state. The Dark Side of The Moon became Pink Floyd’s first number 1 album in the US, remaining on the chart for 741 weeks between 1973 and 1988. One of the best-selling and most critically acclaimed albums of all time. This is the fifth disc of the Immersion Boxset, containing the album and documentaries in high definition.