 Four days later the band reassembled to try a different arrangement . The second version of the song featured McCartney 's Mellotron introduction followed by the refrain . They recorded five takes of the basic tracks for this arrangement ( two of which were false starts ) with the last being chosen as best and subjected to further overdubs . Lennon 's final vocal was recorded with the tape running fast so that when played back at normal speed the tonality would be altered , giving his voice a slurred sound . This version was used for the first minute of the released recording . 
