Tom Hollander was ‘very nervous’ to nail down Truman Capote’s ‘Feud’ accent: It’s ‘almost cartoonish’

FX is closing the door on “Feud: Capote vs. The Swans.”

For the uninitiated, the eight-episode series — ending Wednesday night at 10 p.m. — charts the relationship between acclaimed writer Truman Capote (Tom Hollander) and his coterie of high society friends he dubs the “Swans”: Babe Paley (Naomi Watts), Nancy “Slim” Keith (Diane Lane), CZ Guest (Chloë Sevigny), Lee Radziwill (Calista Flockhart), Ann Woodward (Demi Moore) and Joanne Carson (Molly Ringwald).

Capote’s relationship with the women is irretrievably shattered in 1975 when Esquire magazine publishes his roman a clef, “La Côte Basque, 1965” — titled after the Manhattan restaurant frequented by Capote and the Swans — which paints the women as petty and backstabbing and reveals some of their deeply held secrets. Most of them never forgave him for his literary transgression.

In “Feud,” Capote backslides after being amputated from the Swans. He died in 1984 at the age of 59 at the home of Joanne Carson after years of alcohol and pill addiction.

Hollander, 56, who gives a bravura performance as Capote, spoke to The Post about his on-screen alter ego.

Were you nervous about making Capote’s distinctive voice seem cartoonish?

Yes, I was, because it is almost cartoonish. It’s extreme, but I was very nervous until I wasn’t nervous anymore and that took a few weeks of shooting and people being nice to me, supporting artists, New York folk, coming up to me and saying, ‘That sounds like Truman’ and they had no reason to do that so I kind of believed them. I just did it long enough and I did it with a great voice teacher … so eventually after a couple of months before we started shooting, it was sort of in the muscles of my mouth, and then once it’s in the muscles you can sort of forget about it and soar … and let your emotional register come through a little more. It’s like a musician that knows the Beethoven Sonata so well they can just play it with their heart and don’t have to think about their fingers anymore. That’s what you have to do if you’re doing something extreme like [Capote’s voice].

Do you think Capote regretted publishing the “La Côte Basque” article?

I think so. I’m sure he did. We dramatize that yearning and that sense of loss, but I also think he probably continued to think he could turn it around for some of those nine years. And he was still brilliant — he wrote “Music for Chamelons” later on, a beautiful story. The possibility of redemption was there to the end, otherwise he would have never gotten out of bed.

I think of Capote and the Swans as one organism, and that when Capote was cut off it deprived him of the oxygen he so craved.

I know that’s the story we’re telling in the show. But I suspect that his trajectory was kind of downward anyway; he was such a massive addict and he was unable to deal with that. It’s not a happy story in that respect. My personal feeling is that he was addicted to the Swans and to high society and he was also addicted to alcohol in filling the void inside him when he should have been working. He was getting grander endorphine rushes from his social life and, laterally, his TV appearances, which also gave him an income. He was doing the wrong things … and everyone was trying to tell him that. It’s one of those awful stories where a person knows they’re destroying themself but they can’t stop.

I thought maybe there’s a discreet Truman Capote I can do and I try to make it discreet every so often by finding moments of stillness. Actually, Philip Seymour Hoffman’s completely brilliant performance [as Capote in the 2005 movie “In Cold Blood”] is discreet; for the most part, he’s playing a disciplined, sober Truman in his prime, before he goes completely nuts.

We’re doing a “nuts Truman.”