I read somewhere that, at least early in the group’s career, George Harrison was required to play lead lines given to him by George Martin. Sound familiar to anyone? If true, that would seem to make GM more integral to the formation of the group’s sound than a lot of people realize.
Don’t think so, early GH guitar lines came from Carl Perkins rockabilly, and his solos were surprising awkward and uninspired compared to the high quality of the rest of the Beatle’s work in the studio. So, if GM had a hand in that, he had a tin ear… and that is definitely not true.
The composer’s (Lennon and McCartney) usually had a hook composed with the song (e.g. Day Tripper or I Feel Fine). GM acted as a consultant, usually letting the natural abilities of the boys play out without too much meddling. He did however, usually work hard with the boys on vocal harmonies.
Martin had little experience with rock 'n roll, anyway (he came from producing classical music, and his most successful acts at Parlophone were comedy acts).
Martin was integral to the group’s sound and success, but not by telling George what to play.