Chevalier tells the incredible-but-true story of the "Black Mozart" Joseph Bologne - a swordsman, composer, virtuoso violinist and lover of women in the court of Marie Antoinette.
While you're watching the film Chevalier it's easy to dismiss it as a far-fetched bit of fiction - something from the soapy Bridgerton school of drama, an excuse for a more diverse cast to dress up in an all-purpose Hollywood costume drama.
Far from it. Not only is the story of Joseph Bologne true, it barely covers the facts.
Bologne was born the son of a white, colonial landowner and a slave in Guadeloupe.
The French were apparently rather more liberal than the rest of Europe at the time, and, as a now free Frenchman, young Joseph was admitted to a top school in Paris, where he excelled in fencing and music.
Not only was he a dazzling violinist, he was also a noted composer - the rival, it's said, of another former child prodigy, Wolfgang Amadeus Mozart.
And Chevalier delights in taking a well-known scene from the film Amadeus and turning it on its head. Here, it's Mozart who gets humiliated by an unknown challenger.
Chevalier is clearly out to redress the injustice of Bologne's modern obscurity. In the late 18th century he was one of the great celebrities of the age.
Aside from his astonishing talent, he was young, good-looking and dashing. He moved in the highest social circles. He was even a particular favourite of Marie Antoinette.
But despite being given the title of "Chevalier" - the equivalent of a knighthood - there were still limits and rules. He couldn't marry - certainly not outside his race - though apparently, this being France, a blind eye was turned on his many romantic affairs.
Perhaps that's why he thought he could get away with flirting with Marie, wife of a bad-tempered nobleman.
Marie is played by Samara Weaving - Australian actor Hugo Weaving's daughter - who's attracted as much by Joseph's musical talent as his striking good looks. She's an amateur singer herself.
And of course, one thing leads to another.
Meanwhile, at the other end of the social spectrum, an ageing diva played by Minnie Driver is furious when Joseph scorns her advances.
She stirs up trouble at court, particularly when Joseph announces his ambitions to take over the Paris Opera.
The Queen steps in and decides that the only two candidates are Joseph Bologne and the German, Christoph Gluck. She suggests a contest - the two will each write an opera, and she'll pick the winner.
Joseph calls on the services of Marie to sing in his opera Ernestine, despite Marie's husband forbidding her to do so.
A surprising amount of all this is true - even the part where the cuckolded husband threatens to break the musician's hands, and the fortunate, if anticlimactic, outcome that he doesn't actually do it.
I suspect that the arrival of Mum, and her introduction of Joseph to his musical roots may be slightly less true.
On the plus side, Chevalier looks terrific, particularly star Kelvin Harrison Junior. He's totally convincing both as a fencer and as a ferocious violin player. He and the rest of the cast certainly do what they can with what they're given.
But my reservation is about what they're given.
Apart from regular clunky lines like this, the attitudes in the script remain relentlessly modern-day. Which is a shame because it's a story that's clearly worth telling.
Joseph Bologne was not only a brilliant musician, he was a hero to the growing anti-slavery movements in both Britain and America.
Chevalier offers a chance not only to cast light on a criminally overlooked musical talent but to reassess far more well-known French notables. Marie Antoinette, Voltaire, and even Napoleon all come out firmly on the wrong side of history.
For all its minor strengths, Chevalier's major failing was leaving too much good stuff only to be included in closing titles. In short, a waste of what could have been a great story.
