Quoted in The Beatles Anthology (Ringo) ↑

George Martin was very good

He [George Martin, producer] was very good. In the early days he’d had an assistant who’d go through rehearsals with us and George would just come in for the take, to press the tape button. That changed and he was there all the time; and then, as we went on, we would just be playing, and playing great, and we’d say, “Did you get that, George?” I believe we taught George Martin how to keep the tape rolling. He lost that old attitude that you only press the button when you are going to do the take. We began to have the tape rolling all the time and we got a lot of good takes that way.

Ringo Starr, as quoted in The Beatles Anthology