"Smile," the Brian Wilson album that was famously unheard by the public for nearly 40 years, will be the subject of a Showtime documentary.

"Beautiful Dreamer: Brian Wilson and the Story of Smile" is in production and will debut Oct. 5 on Showtime, the channel announced this week.

The film will include interviews with Wilson, the Beach Boys' creative genius, and footage of February's triumphant "Smile" debut concert in London.

" 'Smile' is the most important piece of music that I ever composed, and I'm thrilled that Showtime feels so strongly about it that they are going to let me tell the story of 'Smile' in this film," Wilson said in a statement.

"Smile" was to have followed the Beach Boys' groundbreaking 1966 album, "Pet Sounds." After carefully crafting the album's multilayered sound, Wilson shelved it shortly before its scheduled 1967 release. He said the songs were "not commercial."

Over the years, "Smile" gained a reputation among fans as the band's lost masterpiece and was hailed by critics at its London debut.