the track, and several sound effects were taped, including 15 seconds of humming and a guitar and a harp-like sound, both to be played backwards; however, none of these were used on the released version. The track was mixed to mono and put aside as the group had decided to release "Lady Madonna" and "The Inner Light" as the single. On their return from India, the group set about recording the many songs they had written there, and "Across the Universe" remained on the shelf. In the autumn of 1968, the Beatles seriously considered releasing an EP including most of the songs for the Yellow Submarine album and "Across the Universe", and went as far as having the EP mastered. World Wildlife Fund version During the February 1968 recording sessions, Spike Milligan dropped into the studio and, on hearing the song, suggested the track would be ideal for release on a charity album he was organising for the World Wildlife Fund. At some point in 1968, the Beatles agreed to this proposal. In January 1969, the best mono mix was remixed for the charity album. In keeping with the "wildlife" theme of the album, sound effects of birds were added to the beginning and end. The original (mono) mix from February 1968 is 3:37 in length. After the effects were added, the track was sped up so that even with 20 seconds of effects, it is only 3:49. Speeding up the recording also raised the key to E-flat. By October 1969, it was decided that the song needed to be remixed into stereo. This was done by Geoff Emerick immediately prior to the banding of the album. "Across the Universe" was first released in this version on the Regal Starline SRS 5013 album No One's Gonna Change Our World in December 1969. This version was issued, in its stereo form, on four Beatles compilation albums: the British version of Rarities, the different American version of Rarities, The Beatles Ballads, and the second disc of the two-CD Past Masters album, released in 1988. The January 1969 mono mix, which had been considered for an aborted Yellow Submarine EP, was finally released on Mono Masters, part of The Beatles in Mono box set, in 2009. Let It Be version The Beatles took the song up again during the Get Back/Let It Be rehearsal sessions of January 1969; footage of Lennon playing the