The truth, Truman Capote believed, is there to be improved on. The writer would have approved of the spry new documentary The Capote Tapes. The recordings in question were made by journalist George Plimpton while researching his 1997 biography of the man he calls “good old Truman”. The tapes went unheard by anyone else until now, and the movie unveils them with the flourish of imminent scandal. In fact — fun as it is to hear Lauren Bacall, Norman Mailer and others reminisce — the audio is just garnish for a story that is mostly public knowledge already. Still, just as friends forgave Capote’s excesses — until they didn’t — you let the poetic licence slide. The result is too damn entertaining not to.

In life, Capote’s fame was large enough for the film to double as a tale of the changing nature of celebrity. (He would have been made for social media.) But as well as zingy, the movie is discreetly traditional — a sturdy account of the life of a great American novelist. The central question director Ebs Burnough asks is why even now he is not quite seen as such. He puts it another way as well. Exactly what kind of writer uses the doe-eyed, pouting headshot Capote did on the jacket of his debut, Other Voices, Other Rooms?

Well, to start with, the kind whose most remarkable creation had always been himself, an abandoned child from Monroeville, Alabama, turned acid-tongued New York insider. One too who saw the page as just one performance among many (and harder work than most). Before he became a fixture on late-night US television, the film unpicks his role as “the entertainment” for the ladies of Manhattan society. But he was also one who wrote like a dream. Breakfast at Tiffany’s made the better movie, but really, we still talk about Capote because of In Cold Blood, his deathless “non-fiction novel” of small-town Kansas crime and punishment. “The rest was just lunch,” says interviewee Jay McInerney. One side-effect of The Capote Tapes may be sending you back to your bookshelves to re-read it.

The sting in the tale comes with Answered Prayers, the novel none of us can read — an unfinished takedown of the New York haut monde that Capote spent years theoretically writing. The entertainment had proved to be a knifeman. Later, the biopics would come, starring actors as gifted as Philip Seymour Hoffman. And yet, as Burnough makes clear, even he could not play Capote as well as good old Truman himself.

★★★★☆

On digital platforms in the UK from January 29