The 5th Dimension's song "Aquarius/Let the Sunshine In" was released in 1969 on their fourth album, The Age of Aquarius. The song was inspired by a performance of the Broadway musical Hair and is considered a showcase of the group's talent and versatility. The song's lyrics are based on astrology and the belief that the world would soon enter the "Age of Aquarius," a time of love, light, and humanity. The song begins slowly with the group's smooth voices and builds to a euphoric ending, blending