Original vocals by Rebecca Page and her mother Ricky Page, who later became The Bermudas and then The Majorettes. The most famous recording of this song for baby-boomers featured Pebbles and Bamm-Bamm on " The Flintstones", although the song was stripped of its religious lyrics for inclusion in the show. In fact the song was recorded at that speed by Stuart Hamblen's wife and adult daughters, so that when played at 45rpm it sounds like a little girl. When played at 33⅓ rpm the vocal sounds more natural. When the Cowboy Church Sunday School version is played at normal speed, 45 rpm, the vocal sounds unnaturally high. Another US recording was made by the McGuire Sisters. The biggest hit version in the United States was a recording by the Cowboy Church Sunday School (peaking at #8 on the Billboard charts) in the United Kingdom, by Joan Regan and her son Rusty. "Open up Your Heart (and Let the Sunshine in)" is a popular song.
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". Root (1854), and all three share the same chord progression IV-I-V-I. 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. The version sung by the McGuire Sisters was featured in the André Øvredal horror film The Autopsy of Jane Doe. It was later used satirically in a scene depicting the religious aspects of 12-step programs. The song was first used as an angelic juxtaposition to the intolerant concept of NIMBY. The version sung by the Cowboy Church Sunday School was featured twice in the John Waters film A Dirty Shame. In fact the song was recorded at that speed by Stuart Hamblen's wife and adult daughters, so that when played at 45rpm it sounds as if it is being sung by children.
The biggest hit version in the United States was a recording by the Cowboy Church Sunday School (peaking at number 8 on the Billboard charts) in the United Kingdom, by Joan Regan and her son Rusty. " Open up Your Heart (and Let the Sunshine In)" is a popular song.