According to Walter Everett the opening chord has an introductory dominant function because McCartney plays D in the bass: Harrison and Martin play F A C G, over the bass D, on twelve-string guitar and piano respectively, giving the chord a mixture-coloured neighbour, F; two diatonic neighbours, A and C; plus an anticipation of the tonic, G – the major subtonic as played on guitar being a borrowed chord commonly used by the Beatles, first in "P.S. I Love You" (see mode mixture), and later in "Every Little Thing", "Tomorrow Never Knows" and "Got to Get You into My Life" (in the latter two against a tonic pedal).