Ethan Hawke is an extraordinary figure. He has made straightforward Hollywood classics like Training Day but he also comes out with those films (Before Sunrise, Before Sunset, Before Midnight) directed by Richard Linklater and co-starring the French actress Julie Delpy which trace the anatomy of an alternative lifetime. Well, now he’s made a film about Lorenz Hart who with Richard Rodgers wrote the most sophisticated songs in American songwriting: ‘The Lady is a Tramp’, ‘Bewitched, Bothered and Bewildered’.

Blue Moon is remarkable and it demonstrates – dazzlingly – that Ethan Hawke can write his own tickets.

He always could. The actor who once partnered Uma Thurman did such stage epics as Stoppard’s The Coast of Utopia and Ethan Hawke is a stage actor who can find the lacrimae rerum in the preposterous gag. Back in 2003 the Lincoln Center was staging a version of Shakespeare’s Henry IV directed by the great Jack O’Brien so luxurious in its casting that the musical comedy star Audra McDonald played the role of Lady Mortimer (the woman who sings in Welsh). Jack O’Brien took the adventurous step of folding parts one and two of the play – the one with Hotspur the fiery rebel and the other with doddering Justice Shallow – into one long play. Kevin Kline was Falstaff but the most remarkable thing was the power and authority Ethan Hawke brought to the role of Hotspur. Who was the dream Hotspur: Colin Farrell, the young Sean Connery? Not Ethan Hawke but he took the part and ran with it and the performance had a staggering authenticity.

Blue Moon is directed by Richard Linklater but it’s a film Hollywood scarcely deserves and it ensures that Ethan Hawke will be remembered forever. We start in a bar where Bobby Cannavale is the barman who allows Lorenz Hart the extra smidgen of whisky that fuels his desolation and his desperate wit. They talk of the affairs of a broken heart, they annotate Casablanca. ‘No one ever loved me that much,’ they quote. Hart makes merry of the fact that Claude Rains is a small man and that he’s left standing, with Bogart, at the end. A young woman, played by Margaret Qualley, loves Hart but not in that way: there’s a story of some hapless young man, who’s left her hanging – and there are stories of Mory’s the all-male club at Yale.

Qualley is magnificent, a lioness of different confusions who later goes off to a party with Richard Rodgers, Hart’s former collaborator. And that’s the tragedy.

It’s 1943 and it’s the first night of Rodgers and Hammerstein’s Oklahoma! and Lorenz Hart can tell instantly that it’s a load of folksy crap. He laughs with self-delectating disgust at ‘the corn is as high as an elephant’s eye’ and all the populist palaver. Imagine, he says, a musical where the hero’s called Curly or the next project: Carousel, all that maudlin treacle.

Andrew Scott plays Richard Rodgers with sympathetic reticence: yes, Hart could fiddle a bit more with songs for a Connecticut Yankee, but why not? There are occasions of pleasantry and pessimism with E.B. White whom Hart thanks for the wisdom of his essays but you know the ship of the great lyricist is sinking before your eyes. It’s a terminal performance, absolutely graceful and impossibly hopeless. Blue Moon is one of those hymns to an America that’s sinking, sinking for the girl Hart will never have, sinking because the impulse to succeed is contraindicated with the intelligence and the frailty of the man who is above it all, the genius who can no longer save himself.

There’s a grim overbearing image of Hammerstein as a man of immense power, a master of the very idiom of success, and a hilarious 13-year-old Stephen Sondheim.

It’s difficult to get your head around the contrapuntal and contrasted bleak humour and the depth of the sadness and wit in this absolutely funny and absolutely doomed portrait of a man of genius who is kind and whose weakness co-exists with something so exquisitely fine and fatally broken. The grog is killing him, maybe so is the lightly sketched sexual ambivalence but the upshot has a towering grandeur with Hawke almost always in shot.

This film asks for comparison with Citizen Kane but it has a sort of vehement burning quality which is literary and has a script that will bear comparison with the greatest American drama and is expressed through peerless direction from Richard Linklater and a central performance from Ethan Hawke which is as great as anything the cinema has produced.

The central paradox of Blue Moon is that Lorenz Hart was the smart guy, the one with the brains to see the joke in every nuanced snatch of beauty.

No one would object to the depiction of the 47-year-old Hart and the girl he adores, impossibly. The logic of the tragedy is that Lorenz Hart gets the cruelty of his own jokes. It’s a lyrical talent, it’s short-breathed and it’s drowned in liquor and a sense of doom that’s mightier than the achievement (though that seems impossibly unfair).

It’s extraordinary though how much feeling Hawke and Linklater get from the story of someone who was never loved the right way, who could never be loved enough.

Of course there’s the paradox that Hart is a more attractive figure to us than the great Rodgers and Hammerstein duo who went on to rule the roost. We adore the great Rodgers and Hart songs, almost forgetting the fact that everyone and her grandmother can sing every note of The Sound of Music just as they applaud the later Cole Porter of Kiss Me, Kate and High Society because it’s a bit like a combination of the Rodgers and Hart songs with dramatic books of a kind.

In the end it doesn’t matter. Blue Moon is a masterpiece of cultural history which is given supreme plangency by the tragedy of a man of genius who can’t help himself. But what Ethan Hawke and Richard Linklater do with Blue Moon is a startling representation of the cruelties of popular culture. It’s also alive to Somerset Maugham highlighting, ‘One loves and the other permits the love’ and an awareness of the bobby-soxer girls screaming for Sinatra. The only show Gene Kelly did on Broadway was Pal Joey. Later, Sinatra filmed it with its crazy songs about strippers who read Schopenhauer.