From the plaintive trumpet that opens the movie to that final killer line — "Forget it, Jake. It's Chinatown" — Roman Polanski's 1974 noir is regarded by film geeks, movie critics and academics everywhere as one of the best American movies ever made. It's one of those rare movies where every scene feels iconic. A fictionalized of some real-life shenanigans pulled by William Mulholland and others who bought the water rights of the Owens rivers out from under the local farmers to feed the burgeoning city of Los Angeles, the movie's depiction of venality and corruption at the highest levels of power struck a nerve with when it came out in post-Watergate America and it's been the template for virtually every noir and thriller to come out since.

"Chinatown" racked up twelve Oscar nominations — including for best picture, best direction, best actor and best actress -- but in the end, the only person to take home a trophy was the screenwriter, Robert Towne. In terms of pacing, dialogue and especially structure, Towne's final script is considered a masterpiece in its own right. "Chinatown" was the first script I read for Screenwriting 101 back in film school.

This week, the Blu Ray for "Chinatown" finally hits the shelves. I talked with Towne over the phone the other day about the movie and about some of the real life LA history that the movie is based on.

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Jonathan Crow: What was the inspiration for "Chinatown"?

Robert Towne: Well, it was a number of things. There was an article in the old L.A West magazine that was kind of an appreciative nod to Raymond Chandler. It was called "Raymond Chandler's L.A" and I hadn't really read much of him, but they did send us some photographs at that time in 1970, the stand for 1936 or 1937. And one was a beautiful Pasadena home with Packard in the porte-cochere. They were noir shots of L.A taken in 1970 and it made me realize that it would be possible to recreate the city of that time period in a way that it would not be possible today. And that got me started thinking about it. "The Last Detail" was stuck in development hell and I was casting them out for something to do and I thought, "I'll try a detective movie." I went to Jack [Nicholson] and talked with him. That was the beginning of it and how the story developed. From there, it was a very lengthy process.

JC: I understand that the first couple of drafts of the script were really painful for you. Is that correct?

RT: Well, parts of it were. I was trying to do something that I've never done before. I wanted to try to do a detective movie but based on a real crime, which was water and power, and I had to make that into a detective story. It involved what was in fact a conspiracy on the part of a bunch of wealthy men to buy up San Fernando Valley and then buy up the water rights of the Owens River and bring it down to L.A. and that show as a conspiracy. That was difficult.

JC: You've made at least three films about the history of Los Angeles. What is it about L.A that draws you?

RT: It's a town of transients and it always has been. Up until 70 or so years ago, most people spent their lives in one town. But here's a town where people escape wherever they were and start a new life. And they didn't know each other; they were lost. That gave rise to a lot of desperation and a lot of oddball crimes. The whole Charlie Manson story, this is a place that was made for that because people didn't know anybody's past. They had no place in that society, which is what drew those people to Manson. L.A is rife with crimes like that.

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JC: "Chinatown" has been so influential I think in the way people see Los Angeles that the story of the movie has, in many people's minds, supplanted the actual history. How do you feel about that?