- John Lennon - double-tracked lead vocal, rhythm guitar, harmonium
- Paul McCartney - bass guitar, harmony vocal
- George Harrison - double-tracked lead guitar, maracas
- Ringo Starr - drums
Doctor Robert is mainly a John Lennon composition with collaboration from Paul McCartney. It was written for the Revolver album in the UK, and then was released on Yesterday and Today in the US. Doctor Robert was recorded on April 17, 1966 in a total of 7 takes. (Vocal overdubs were added a couple of days later.) John sings lead and plays rhythm guitar and harmonium. The others play their usual instruments and roles, except that George, and not Ringo, added the maracas. The song is rather explicitly about taking "feel-good" pills- It is said to be the Beatles' first song to mention the subject of drugs, though few commented on it at the time. Many have wondered who the real "Doctor Robert" was, but John once said it was a reference to himself, as he "carried the pills" on tour in the early days. Many suspect the reference was to Dr. Robert Freyman, a reported purveyor of amphetamines to the affluent on Manhattan's East Side.