"Open Up Your Heart (And Let the Sunshine In)" (sometimes seen as "Open Up Your Heart") is a popular song written by Stuart Hamblen and first published in 1954.
The original version was by the Cowboy Church Sunday School and was a hit in the United States, peaking at number 8 on the Billboard charts. Another widely known US recording was released shortly after by the McGuire Sisters, and the United Kingdom saw a version by Joan Regan and her son Rusty.
When the Cowboy Church Sunday School version is played at normal released speed, the vocals sound unnaturally high. When played at 33â  rpm instead of 45 rpm the vocals sound more natural. The song was recorded at 33â  rpm speed, by Stuart Hamblen's two daughters (19 & 18 years old at the time of this recording), so that when played at 45 rpm the song sounds as if it is being sung by children.
The version sung by the Cowboy Church Sunday School was featured twice in the John Waters film A Dirty Shame. The song was first used as an angelic juxtaposition to the intolerant concept of NIMBY. It was later used satirically in a scene depicting the religious aspects of 12-step programs. "The Hamblens" sung the version featured in the André ÃÂvredal horror film The Autopsy of Jane Doe.
The melody of the chorus section is identical for its first two measures to the published version of "Aloha Oe" by Princess Lili`uokalani (1878), and "There's Music in the Air" by George F. Root (1854), and all three share the same chord progression IV-I-V-I.
The 1969 number 1 hit song "Aquarius/Let the Sunshine In" by The 5th Dimension contains the refrain "Let the Sunshine In" and backing vocals that include the phrase "Open Up Your Heart".