The Performance: Andy Serkis as Ian Dury in ‘Sex & Drugs & Rock & Roll’

In a biopic of a wild-eyed, libertine, punk-era wordsmith, some poetic licentiousness is to be expected. Rocker Ian Dury, the subject of “Sex & Drugs & Rock & Roll,” has even said, “Never let the truth get in the way of a good story.” So what to make of an early scene in the film in which he’s raucously rehearsing with his band in the living room — as his wife gives birth to their son upstairs?

“A true event,” says Andy Serkis, who stars as Dury. His wife Betty, Serkis says, “had to come down and say, ‘Could you please shut up?’ It’s absolutely true.”

The film, which opens Friday, is not the standard greatest-hits tour of a famous musician’s life, rather something more impressionistic — vignettes conveying the man’s energy and demons.

“The most extreme things are actually the most truthful: The Christmas dinner scene, when he spikes his wife’s new lover’s dinner with hash. That really happened; that came from [Dury’s son] Baxter. There’s a letter on screen that Ian writes to [daughter] Jemima; that’s the actual letter he wrote to her,” says Serkis. “They went to the lockup where they put all his costumes and stuff and brought it all out for the film.”

Serkis’ performance has already won the best actor prize from the Evening Standard British Film Awards and scored nominations for BAFTA, British Independent Film and London Critics’ Circle awards after its earlier opening in the U.K. The actor cites a number of similarities between himself and the late Dury — both are painters and fathers from fatherless homes, and they’re politically simpatico. Serkis says this in a voice within range of Dury’s rock-quarry basso profundo, but much nicer.

“I was about 14 when [Dury’s] ‘Hit Me With Your Rhythm Stick’ came out; I remember listening to it on the radio going off on a camping trip — ‘Who is this man and what is this extraordinary sound, these incredible lyrics?’ He had this unique voice but was also this unbelievably colorful, idiosyncratic performer, the likes of which I’d never seen.”

Although Dury is one of the godfathers of the punk movement, his music was really a mix of working-class anger, Ornette Coleman-era jazz, white funk and ornate lyrical assaults barked by a limping, sneering cabaret showman.

“He was very much a Brechtian song spieler; his songs are like sung poems. And he’s sort of an emcee character of his own life in the film,” Serkis says.

“Here’s this man who really shouldn’t have been a rock ‘n’ roll star. He was crippled from polio, he couldn’t particularly sing very well, he was too old to be a rock musician, really — being in your late 30s isn’t a great place to start with a cutting-edge band. But he was a brilliant lyricist and managed to engage with a vernacular that was very much the voice of the people.”

Polio wasted away the left side of Dury’s body, which Serkis approximated by losing about 24 pounds while studiously working out only his right side, leaving his left smaller and weaker. For the actor, it was worth it to portray such a singular figure — if not such a pleasant one.

“I actually had the chance to meet him in the mid-’90s. The meeting wasn’t great, I have to say,” Serkis says, chuckling. “He was very much out of order. He didn’t suffer fools, put it that way, and he’d had a few to drink. But I was very glad, when I got to play the role, that I’d seen that side of him. As we started working with the family and [those who knew him], we showed them the script and they said, ‘Well, he was much more of a so-and-so than that!’

“We showed the film to [the family] … I think that was probably the most nerve-racking day. They were really moved and grateful; they sent us an e-mail the next day saying, ‘Ian would have laughed — and then coated you off with great affection,’ which is a Cockney expression for giving you a slap, actually.”

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