<P> The Dark Side of the Moon is the eighth studio album by English rock band Pink Floyd, released on 1 March 1973 by Harvest Records . It built on ideas explored in Pink Floyd's earlier recordings and performances, but without the extended instrumentals that characterised their earlier work . Its themes explore conflict, greed, time, and mental illness, the latter partly inspired by the deteriorating health of founding member Syd Barrett, who left in 1968 . </P> <P> Developed during live performances, Pink Floyd premiered an early version of The Dark Side of the Moon several months before recording began . New material was recorded in two sessions in 1972 and 1973 at Abbey Road Studios in London . The group used advanced recording techniques at the time, including multitrack recording and tape loops; analogue synthesizers are prominent, and snippets from interviews with Pink Floyd's road crew and others provide philosophical quotations . Engineer Alan Parsons was responsible for many sonic aspects and the recruitment of singer Clare Torry, who appears on one track . The iconic sleeve was designed by Storm Thorgerson; following keyboardist Richard Wright's request for a "simple and bold" design, it depicts a prism spectrum, representing the band's lighting and the record's themes . </P> <P> The Dark Side of the Moon produced two singles: "Money" and "Us and Them". The album topped the Billboard chart for a week, and remained on the chart for 741 weeks from 1973 to 1988 . Following a change in how Billboard counts sales in 2009, it re-entered the chart and has since appeared for over 900 weeks . With estimated sales of over 45 million, it is Pink Floyd's bestselling album and one of the bestselling worldwide . It has been remastered and rereleased several times, and covered in its entirety by several acts . It is regarded as one of, and often the, greatest album of all time . </P> <P> Following Meddle in 1971, Pink Floyd assembled for a tour of Britain, Japan and the United States in December of that year . In a band meeting at drummer Nick Mason's home in Camden, bassist Roger Waters proposed that a new album could form part of the tour . Waters' idea was for an album that dealt with things that "make people mad", focusing on the pressures faced by the band during their arduous lifestyle, and dealing with the apparent mental problems suffered by former band member Syd Barrett . The band had explored a similar idea with 1969's The Man and The Journey . In an interview for Rolling Stone, guitarist David Gilmour said: "I think we all thought--and Roger definitely thought--that a lot of the lyrics that we had been using were a little too indirect . There was definitely a feeling that the words were going to be very clear and specific ." </P>

How many copies of the dark side of the moon sold