Pink Floyd recorded The Dark Side of the Moon between May 1972 and January 1973, with EMI staff engineer Alan Parsons at Abbey Road. The title is an allusion to lunacy rather than astronomy.[103] The band had composed and refined the material on Dark Side while touring the UK, Japan, North America and Europe.[104] Producer Chris Thomas assisted Parsons.[105] Hipgnosis designed the album’s packaging, which includedGeorge Hardie‘s iconic refracting prism design on the cover.[106] Thorgerson’s Dark Side album cover features a beam of white light, representing unity, passing through a prism, which represents society. The resulting refracted beam of coloured light symbolises unity diffracted, leaving an absence of unity.[107] Waters is the sole author of the album’s lyrics.
Reference: http://en.wikipedia.org/wiki/Pink_Floyd