Halfway through 1972, Pink Floyd entered Abbey Road studios to record a concept album they had been performing in it's entirety during their concerts. Initially titled "Eclipse: A Piece for Assorted Lunatics," Dark Side of the Moon has become an interesting peice of rock and roll history. The cover depicts a prism which is meant to represent the light shows that the band was known for during their performances. Alan Parsons had made a name for himself engineering The Beatles' Abbey Road, but Dark Side of the Moon was what put him on the map. He allegedly swapped shifts with other employees in order to be involved with as much of the album as possible. The album spent 741 weeks in the Billboard Top 100...that's not a typo, 741 weeks (591 consecutive weeks was the longest run it had). With songs like "Time," "Money," "Brain Damage," and the opus "Eclipse," it's no wonder. This was the first album that featured all the lyrics written by Roger Waters, who would go on to craft several concept albums on his own and with Pink Floyd.