he later said : personnel john lennon double-tracked vocal , acoustic guitar paul mccartney bass , harmony vocal george harrison double-tracked sitar ringo starr tambourine , maraca , finger cymbals reception and legacy the song is described by writer mark lewisohn as '' pure lennon genius ... one of the most original pop music songs recorded to date '' , and by music critic richie unterberger as '' undoubtedly the beatles ' greatest lyrical triumph during their folk-rock phase '' .