After hearing just a rough demo tape, George Martin brought the Beatles to Abbey Road studios to clean up some of their material, which already included “P.S. I Love You” and “Love Me Do.” When Martin asked the band if they saw anything out of place, George Harrison responded, “Well, there’s your tie, for a start.”

In the Hollywood version of this story, the cool, young rock ‘n’ rollers would probably sheer off the square old producer’s tie and stick it to the door of the studio. But Martin—a well-dressed chap a generation ahead of the scruffy band—just laughed it off. And then he made every track in that session a hit.

“If anyone earned the title of the fifth Beatle, it was George,” Paul McCartney wrote today, when Martin passed at 90 years old.

You can hear Martin’s influence on the band everywhere from his dramatic string arrangement behind McCarney’s solo “Yesterday” to the dramatic arrangement of “Eleanor Rigby.” But where you truly hear a great producer is in the gaps between the notes. Martin’s specialty was walking into a room, hearing four musicians play eleven disparate parts and telling them to go with the second, fourth and ninth pieces. While there might be coffee mugs for “World’s Best Boss,” there are precious few in the world.

In the example of “Yesterday,” Martin’s leadership was striking, even when the band hated the idea of adding strings. McCartney wrote, “George Martin said to me, ‘Paul I have an idea of putting a string quartet on the record.’ I said, ‘Oh no, George, we are a rock and roll band and I don’t think it’s a good idea.’ With the gentle bedside manner of a great producer he said to me, ‘Let us try it and, if it doesn’t work, we won’t use it and we’ll go with your solo version.’ I agreed to this and went round to his house the next day to work on the arrangement. He took my chords that I showed him and spread the notes out across the piano, putting the cello in the low octave and the first violin in a high octave and gave me my first lesson in how strings were voiced for a quartet. When we recorded the string quartet at Abbey Road, it was so thrilling to know his idea was so correct that I went round telling people about it for weeks.”

Working with creative people is a challenge, but the true skill of showing artists how their own ideas can flourish (in this case, just letting a few guitar chords bloom) is something so close to alchemy that it’s no wonder they gave him so many golden records.