Bass (specifically a Fender Jazz bass, though often debated). George Harrison: Electric guitar. Ringo Starr: Drums.
The track is legendary for its closing dialogue, where Paul shouts, " Keep that one, mark it fab! " after the band crashes to a halt. Personnel & Instrumentation: Paul McCartney: Lead vocals and electric guitar. helter_skelter_second_version_take_17
Watch the official visualiser for this legendary outtake to hear the raw intensity Paul and the band brought to the studio: Bass (specifically a Fender Jazz bass, though often debated)