Aquarius/Let the Sunshine In

"Medley: Aquarius/Let the Sunshine In (The Flesh Failures)" (commonly called "Aquarius/Let the Sunshine In", "The Age of Aquarius" or "Let the Sunshine In") is a medley of two songs written for the 1967 musical Hair by James Rado and Gerome Ragni (lyrics), and Galt MacDermot (music), released as a single by American R&B group the 5th Dimension. The song spent six weeks at number one on the US Billboard Hot 100 pop singles chart in the spring of 1969 and was eventually certified platinum in the US by the RIAA. Instrumental backing was written by Bill Holman and provided by a group of session musicians commonly known as "the Wrecking Crew".

The song is listed at number 66 on Billboard's "Greatest Songs of All Time".

History
The recording was led by veteran American producer and engineer Bones Howe, who had previously worked with the 5th Dimension as well as the Mamas & the Papas and Elvis Presley. As Howe tells it, the recording can be traced to an incident in which 5th Dimension lead singer Billy Davis Jr. left his wallet in a New York City cab; the man who found the wallet was involved in the production of Hair and invited the group to see the show: "After they'd seen it I received a phone call in which they were all talking over one another, saying 'We've got to cut this song "Aquarius". It's the best thing ever.'"

Howe was skeptical ("This isn't a complete song. It's an introduction."), but after seeing the show on stage got the idea to create a medley with another musical moment from the show, a few bars from the song "The Flesh Failures" that consist of the repeated words "let the sunshine in". Although the two song fragments are in different keys and tempos, Howe resolved to "jam them together like two trains".

The instrumental track was set to tape at Wally Heider's Studio 3 in Hollywood by the Wrecking Crew members including Hal Blaine on drums, Joe Osborn on bass, Larry Knechtel on keyboards, Tommy Tedesco and Dennis Budimir on guitars and Tony Terran on trumpet. It also featured strings, winds, and brass instrumentations. However, the vocals were recorded separately in Las Vegas, where the 5th Dimension was performing at the time, using only two microphones for the five singers. Davis' solo during "Let the Sunshine In" was improvised during the session; songwriter Jimmy Webb, who happened into the studio during the recording, remarked to Howe: "My God, that's a number one record."

This song was one of the most popular songs of 1969 worldwide, and in the United States it reached the number one position on both the Billboard Hot 100 (for six weeks in April and May) and the Billboard Easy Listening chart. It also reached the top of the sales charts in Canada and elsewhere. Billboard ranked it as the No. 2 Hot 100 single for 1969, although "Aquarius (Let the Sunshine In)" would go on to outsell the No. 1 Hot 100 single for 1969, "Sugar Sugar" by The Archies, and consistently ranks several positions above it in the all-time chart.

The recording won both the Grammy Award for Record of the Year and Best Pop Vocal Performance by a Group for the Grammy Awards of 1970, after being published on the album The Age of Aquarius by the 5th Dimension, and also being released as a seven-inch vinyl single record. In 2004, the song was inducted into the Grammy Hall of Fame.

The lyrics of this song were based on the astrological belief that the world would soon be entering the "Age of Aquarius", an age of love, light, and humanity, unlike the current "Age of Pisces". The circumstances for the change are given as: "When the moon is in the seventh house, and Jupiter aligns with Mars." Astrologer Neil Spencer denounced the lyrics as "astrological gibberish", noting that Jupiter forms an astrological aspect with Mars several times a year and the moon is in the 7th House for two hours every day.

The American Film Institute's 100 Years...100 Songs list, published in 2004, ranked "Medley: Aquarius/Let the Sunshine In (The Flesh Failures)" as number 33.