"Aquarius/Let the Sunshine In", sometimes incorrectly known as "The Age of Aquarius" or "Let the Sunshine In", is a medley of two songs from the musical Hair ("Aquarius" and "The Flesh Failures (Let The Sunshine In)") written by James Rado, Gerome Ragni and Galt MacDermot, and released as a single in 1969 by The Fifth Dimension. The single held the number one position on the U.S. Billboard Hot 100 for six weeks and was certified Platinum.[
The Fifth Dimension, also known as The 5th Dimension, is an American popular music vocal group, whose repertoire also includes pop, R&B, soul, and jazz.
The Fifth Dimension were best-known during the late 1960s and early 1970s for popularizing the hits "Up, Up and Away" and "Aquarius/Let the Sunshine In." The recording won the Grammy Award for Record of the Year and Best Contemporary Vocal Performance by a Group at the Grammy Awards of 1970, after it was released on the album The Age of Aquarius.
The song was based on the astrological belief that the world would be entering the Age of Aquarius, an age of love, light and humanity, unlike the then current Age of Pisces. This change was presumed to occur at the end of the 20th century.
"Aquarius/Let the Sunshine In" was ranked thirty-third on the 2004 AFI's 100 Years... 100 Songs.
The five original members were Billy Davis, Jr., Florence LaRue, Marilyn McCoo, Lamonte McLemore, and Ron Townson. They have recorded for several different labels over their long careers. Their first work appeared on the Soul City label, which was started by Imperial Records/United Artists Records recording artist Johnny Rivers. The group would later record for Bell/Arista Records ABC Records and Motown Records.
Some of the songwriters popularized by The Fifth Dimension later went on to careers of their own, especially Ashford & Simpson, who wrote "California Soul". The group is also notable for having more success with the songs of Laura Nyro than Nyro did herself, particularly in the cases of "Wedding Bell Blues", "Stoned Soul Picnic", and "Save the Country". The group also covered music by well known songwriters such as the song "One Less Bell to Answer" written by Burt Bacharach and Hal David.