Just found this 'study' on Rain and Paperback Writer. A long shot, but some interesting points of view.
General Points of Interest
Style and Form
For all of its musical and technical innovation, it's a bit ironic to note how standard is the form and harmonic content of this song.
Though no sitars or other ethnic "world music" instruments are used here, the style of the song very much connotes the style of classical Indian music by virtue of the droning harmony and the, at times florid tune.
Melody and Harmony
As far back as "Love Me Do" (amazingly), John and Paul had stumbled onto a novel use of spicy little trills and languorously stretched out melismas that, along with sung open and parallel fifths, is truly one of the more subtle trademarks of their early "sound". Here, what is essentially the identical technique is pushed beyond the routine envelope to create an entirely new and exotically "foreign" effect.
Aside from ornamentation, the tune is structurally organized in a very "Indian" manner; with the approximate two halves of the melodic octave each isolated to its own respective section of the song; the verse stays carefully within low G up to E, while the refrain deals with the upper end of the octave, from the high G down to middle C.
The harmonic budget is frugal to the extreme of creating, what I can only assume is, an intentionally static effect. You'd expect the use of I -
