Smile is an unfinished album by the American rock band the Beach Boys, conceived as the follow-up to their 1966 album Pet Sounds. The project—a concept album involving themes of Americana, humor, youth, innocence, and the natural world—was planned as a twelve-track LP assembled from modular fragments, the same editing process used on their single "Good Vibrations". After a year of recording, the album was shelved and a downscaled version, Smiley Smile, was released in September 1967. The original project came to be regarded as the most legendary unreleased album in popular music history.