If there are death triads, he fits with Nancy Reagan, who made Ronald Reagan the Reagan we know. (Didn't she?)

The NYT has a lovely obituary, written by Allan Kozinn. Excerpt:
In the dozen years before he met the Beatles, Mr. Martin produced symphonic, chamber and choral recordings, jazz albums and a string of popular comedy records by Peter Ustinov, Peter Sellers and Spike Milligan. In the 1960s, as the recordings he made with the Beatles rode the top of the charts, he also produced hits by other British Invasion acts, among them Gerry and the Pacemakers, Cilla Black, and Billy J. Kramer and the Dakotas. He later worked with a diverse roster of pop and jazz performers, including Ella Fitzgerald, the Bee Gees, Jeff Beck, the Mahavishnu Orchestra, Paul Winter, Cheap Trick, America and Ultravox....

When the Beatles played “Please Please Me” for him for the first time... it was in a slow arrangement meant to evoke the style of Roy Orbison, one of their heroes. Mr. Martin told them the song sounded dreary, and insisted that they pick up the tempo and add a simple harmonica introduction. His suggestions transformed “Please Please Me,” which became their first big hit.
My son John — who has studied The Beatles more than I would have thought possible — writes:
George Martin wasn't just a great producer who happened to work with the greatest rock band of all time. There's a reason he's called the fifth Beatle, but even that honorific fails to capture what he really did. He didn't merely provide so many studio innovations that it's possible to pick out many Beatles songs where his effect on the finished product was at least as important as that of some of the actual Beatles. He radically challenged every preconception of what a rock band was supposed to be, in a way that didn't just change what the Beatles sounded like, but changed the next 50 years of music.
John quotes a passage from the Ian MacDonald book "Revolution in the Head: The Beatles' Records and the Sixties":
Lennon wandered into an antiques shop and picked up a Victorian circus poster advertising . . . a show put on by some travelling tumblers . . . in 1843. This appealed to his sense of the ridiculous and, when the new album [Sgt. Pepper's Lonely Hearts Club Band] called for another composition from him, he hung the poster on the wall of his home studio and, playing his piano, sang phrases from it until he had a song. Taking it to Abbey Road, he asked George Martin for a "fairground" production wherein one could smell the sawdust — which, while not in the narrowest sense a musical specification, was, by Lennon's standards, a clear and reasonable request. (He once asked Martin to make one of his songs sound like an orange.) While The Beatles' producer worked more naturally with the conventionally articulate McCartney, the challenges of catering to Lennon's intuitive approach generally spurred him to his more original arrangements, of which Being for the Benefit of Mr. Kite! is an outstanding example. Using harmonium, harmonicas, and a tape of Victorian steam organs and calliopes cut up and edited into a kaleidoscopic wash, he created a brilliantly whimsical impression of period burlesque, ideally complementing Lennon's dry nasal delivery. Few producers have displayed a tenth of the invention shown here.
 ADDED: Here's George Martin explaining his work on "Please Please Me":



AND: Here's a whole 51-minute BBC documentary about George Martin: