The set is the follow-up to The Pet Sounds Sessions (1997), this time focusing on the abandoned recordings from the band's unfinished 1966–1967 album Smile.

It features comprehensive session highlights and outtakes, with the first 19 tracks comprising a hypothetical version of the completed Smile album.

The compilation is the first and only package devoted to the 1960s Smile recordings originally produced by Brian Wilson, arriving after decades of public anticipation and numerous false starts.

Plans for a Smile archival release go back to at least early 1980s, when it was proposed that the album be issued in some form.

A comprehensive and official package dedicated to the original Beach Boys' recordings had not been compiled partly due to the logistics in organizing the dozens of convoluted song components.

[4] It was originally planned as a three-CD set, but ultimately grew to five CDs, with two of those devoted solely to the sessions for "Heroes and Villains" and "Good Vibrations", respectively.

[10] The reconstruction is presented in monaural due to missing stems and as a nod to Wilson's producing methods at the time.

For instance, on "Surf's Up", the instrumental track was mashed up and synced with the vocal stem from an alternate performance of the song.

"[7] A list of notes on the reconstructed album assembly were given in the booklet: On February 3, 2011, Al Jardine told an interviewer that "Capitol Records plans to issue a Beach Boys version of Smile sometime this summer to begin the celebration of the Beach Boys’ 50th anniversary.

[3] Pitchfork reviewer Mark Richardson gave the album a perfect score and wrote, "What's here is brilliant, beautiful, and, most importantly, finally able to stand tall on its own.

"[28] Rolling Stone's David Fricke declared in his review, "there is delight and confidence in Wilson's exchanges with his studio crew.

"[23] Writing in LA Weekly, musician Henry Rollins praised the compiled recordings as "even better than advertised ... Sonically, the album is one of the best things you are likely to hear in all of your life.

"[29] PopMatters' Thomas Britt wrote "There is something holy in the tapestry of the album" and when reflecting on the drama surrounding the album's history stated "Contemporary bands could certainly stand to realize that all the band myths and stories in the world don’t matter much if you can't bring the songs, and no one brought the songs like Brian Wilson.