In addition to a remix of the original album, the expanded 50th Anniversary Edition, out today, include three discs of unreleased material. The first, from the initial day with Starr and Voormann, includes all 15 of those tunes played by the trio; a second disc consists of Harrison solo demos of another 15 songs, including George-unplugged versions of Wah-Wah (his wry commentary on Beatles meetings) and Beware of Darkness.

The third, which Harrison’s son and the reissue’s executive producer Dhani calls “the party disc,” features alternate takes, unheard jam sessions, and studio chatter from Harrison and the pile-on of musicians — Peter Frampton, Billy Preston, Dave Mason, and Eric Clapton and the other Dominos — who contributed to the album.

Equally fascinating, the core All Things Must Pass has been subtly remixed — both to bring added sonic clarity to Spector’s lovingly dense and echo-heavy arrangements and to adhere to Harrison’s own wishes before his death in 2001. “He hated the reverb,” Dhani says. “He said this to me and Paul a million times: ‘God, that reverb!’” Voormann also recalls Harrison making similar comments to him years later about the multiple overdubs: “I remember him saying, ‘It’s too much,’” Voormann says.