What do we know about Leonard Bernstein, who did everything to popularise classical music and wrote the Broadway classic West Side Story? He was bisexual and he conducted the legendary performance of Beethoven’s Ninth in 1989 when the Wall came down. Bradley Cooper disdains to use this spectacular biopic moment in Maestro, his reflective and masterly film about Leonard Bernstein. We first see him in his sixties and we gasp at the physical resemblance that Bradley Cooper achieves. This is a staggeringly fine performance in what is essentially a quiet yet heartbreaking story about the loves we treasure and indulge and see dislocated or desecrated.

Cooper’s Bernstein in age is like the great Jewish showman of genius brought to life in facsimile. It is a dazzling piece of portraiture but it exists not as a piece of cinematic photo realism but as a signature of authenticity.

Maestro is intimately concerned with the fact that Bernstein will not give up the boys and the way this impacts his marriage.

The early Bernstein is less literally reproduced but there is a graphically economical indication of physicality here and there even though we’re never made inward with agonies of choice or self-definition. It is more that Maestro is an examination of Bernstein’s refusal to compromise with his desires and this is presented by Cooper, both as director and actor, with a coolness which is the opposite of sentimental and which comes across as both lethal and inevitable.

We see only the casual gestures of flirtatiousness, of a rampant, half-egotistical devotion to musical prowess – something which is by necessity taken for granted rather than part of a weighted hetero/homo dialectic. But the way in which Cooper’s Bernstein takes his pleasure as an absolute right continuous with his artistry is more chilling in its devotion to the cult of the self than we expect any Hollywood portrait of stardom to come within spitting distance of.

It is a magnificent performance: flinty, impervious, with a half-conscious cruelty that is no stranger to sadness even if it is with the credible face of a narcissism that makes his artistry possible. This is a mightily austere film and only its understatement, and its lack of melodramatic accentuation make you doubt that Cooper will win every award for best director and best actor in sight. He shows reserves that are all but undreamt of in Hollywood in this area.

Maestro was produced not only by Cooper but by both Martin Scorsese and Steven Spielberg. It is shot on film and has an iridescent silvery quality jumping from a box-sized 35mm screen in a lustrous black and white that irresistibly and massively recapitulates the Fifties to the strong command of Seventies and Eighties colour as the natural medium for any representation of credible human life.

Cooper has an enormous advantage in Maestro of Carey Mulligan as his wife Felicia Montealegre. She has married him knowing the patches of darkness that exclude her and it’s only much later that we learn, from her, how long it took Bernstein to accept her in marriage. We see her palpably in love with him as a bubbling young actress and then later the gradations of pain and humiliation that are continuous with the choices she’s made and the choices that have been made for her. Mulligan captures with an extreme vertiginous grace the ways in which love can co-exist with gulfs of disappointment and this performance is luminous and ravaged all at once. She does that exceptionally difficult thing of playing a character significantly older than she is (she is 38) but still middle-aged. She has a breathtaking charm and stillness which is in no way contrived though the overall effect she creates with the character is tremendous in its tragic power.

World-shattering things happen with the glide of the camera in Maestro. We feel sympathy for positions we share or fail to because they are presented in such a life-like way. This is a film about endurance and fragility. It has a formal beauty – it is magnificently shot by Matthew Libatique – and the power of dramatic implication that is at the furthest remove from Hollywood hyperbole and perhaps has a bit in common with Ingmar Bergman in a very implicit throwaway fashion, not at all histrionic in rendering the impassable waters of emotional estrangement which are so ordinary we barely recognise the poignancy that confronts us.

This is an adult film about a famous artist and composer who is, among a world of other things, torn between being a dazzling performer and interpreter and achieving the satisfaction of the true towering expressiveness of the solitary artist, the composer, the shaper of music. Cooper demonstrates both things at once. Maestro is a great film about a man who will not compromise his calls to act out his sexuality and it is also indelibly and undeniably a work of art.

It creates with an extraordinary dynamism the cut-glass elegance of 1950s America and does not put a foot wrong whether in its snippets of Ed Sullivan or the way in which Mulligan adapts herself to the natural elegance of the world in which she finds herself. And she also stands out, her face older and broader with pain and puzzlement.

The supporting cast is magnificent. Maya Hawke – the daughter of Uma Thurman and Ethan Hawke – stumbles on the rumours about Bernstein, her father, and Mulligan says to him he must not dare to tell her the truth. He fobs her off with talk of jealousy.

Maestro is a film that will create its own form of jealousy because it is so plainly the work of a master who believes in both the magnitude of his stars – Mulligan is on par with Katharine Hepburn at the height of her powers – and the necessity of allowing his ensemble to sparkle and shine as an enchantment of a backdrop.

Maestro is a superb piece of historical recapitulation which is also so much more. It contains multitudes you can easily miss.

Everyone should take a look at it on Netflix. Just bear in mind this is an unflinching examination of the reasons of the heart the reason knows not of.