Dylan introduced The Beatles to marijuana which led to everything from LSd to heroin. I think because of that you would have to say that Dylan influenced their sound more than any one person. Running tape backwards to create certain passages in the Sargent Pepper and Magical Mystery Tour came about when one evening when John was tripping on LSD and listening to music he realized the tape on the reel to reel was being played backwards.
As John would go on to say
I don't believe in Elvis
I don't believe in Zimmerman
I don't believe in Beatles
I just believe in me
Yoko and Me
That's reality.
As John would go on to say
I don't believe in Elvis
I don't believe in Zimmerman
I don't believe in Beatles
I just believe in me
Yoko and Me
That's reality.