The Dark Side of the Moon is the eighth studio album by the English progressive rock band Pink Floyd. It was released in March 1973. The album built on ideas explored in the band's earlier recordings and live shows. It lacks the extended instrumental excursions that characterized their work following the departure in 1968 of founding member, principal composer and lyricist Syd Barrett. The Dark Side of the Moon's themes include conflict, greed, the passage of time, and mental illness, the latter partly inspired by Barrett's deteriorating mental state.

The group used some of the most advanced recording techniques of the time, including multitrack recording and tape loops. Analogue synthesizers were given prominence in several tracks, and engineer Alan Parsons was directly responsible for some of the most notable sonic aspects of the album as well as the recruitment of performer Clare Torry.

The album's iconic sleeve, features a prism that represents the band's stage lighting, the record's lyrical themes, and keyboardist Richard Wright's request for a "simple and bold" design.

The Dark Side of the Moon was an immediate success, topping the Billboard Top LPs & Tapes chart for one week. It subsequently remained in the charts for 741 weeks from 1973 to 1988. An estimated 50 million albums were sold and it is consistently ranked as one of the greatest albums of all time.

More Info: encyclopedia.thefreedictionary.com