The Beach Boys' "Smile" is considered the most legendary unreleased album in the history of popular music. Recorded in 1966 and 1967, "Smile" was to be the followup to the album "Pet Sounds" (1966), but due to a plethora of reasons including project leader Brian Wilson's deteriorating mental health and increased friction among the band members as well as between the band members and the record company executives, the band abandoned the project after completing numerous recordings slated for the project (which were included in later, less ambitious albums). In 2004, Wilson and writing partner Van Dyke Parks went into the studio, and newly recorded the material and released it as a completed solo album. That album was used as a template to construct a version of the Beach Boys album from the original Smile Sessions in 2011.