With those darting eyes, sinister glare and a voice that could cut leather, Patrick McGoohan was an actor born to play Iago. But the only time the American-born, British-and-Irish-raised star of “Danger Man” (“Secret Agent Man” in the States), “The Prisoner” and more than his share of films and plays ever got to tackle one of Shakespeare’s great villains was in a movie set in the world of jazz.

“All Night Long” is a shadowy, inky-black/milky white and oh-so-hip artifact, a film full of jazz and jazz greats and Patrick McGoohan at his most villainous, set in London on the cusp of the “Swinging ’60s. Even if it isn’t the most satisfying and edgy modernization of “Othello,” it’s got the cast and camera work of a classic.

And in McGoohan, it’s got a great Iago, here named Johnny Cousin — “Cousin Johnny” in the jazz world — a drummer with big band dreams and devious means of achieving them.

Nel King and Paul Jarrico — a Blacklisted screenwriter who was “Peter Achilles” in the film’s credits — turned Shakespeare’s story of mistrust and treachery into a single-night-in-the-1960s drama with interracial marriage and pot-smoking jazzmen as titilating subtexts.

Veteran director Basil Dearden (“Frieda,” “Dead of Night”) and “The Third Man” cameraman Ted Scaife shot “All Night Long” as a late nod to film noir and editor John D. Guthridge helped turn their arresting images into a veritable long-form jazz music video. Real players appeared in supporting roles — Dave Brubeck and Charles Mingus have a duet, and John Dankworth, Tubby Hayes and others pitched in writing tunes and playing in the big ensemble formed and reformed here during this jazz party, playing themselves.

McGoohan? He learned to play the drums and had a drumming coach on set. The sinister scheming part of the role came naturally.

A rich Brit jazz fan (Richard Attenborough) throws a surprise party for a couple of London jazz luminaries, piano-playing bandleader Rex (Paul Harris) and his wife of one year, former jazz singer Delia (Marti Stevens).

Rod Hamilton is such a jazz fan that he turned a warhouse into a multi-level flat with a big open living room built for loud parties and live performances by his many friends in jazz. Mingus is there, practicing his upright bass when Rod gets home.

The surprise party may have a second “surprise,” as Delia’s been rehearsing a number to sing for her husband, despite his wish/command that she retire. The snarkier of the evening’s guests, at drummer Johnny’s prompting, note the “solitary confinement” an accomplished singer agreed to when she married the controlling Rex, who figures he’s “gotten her properly trained,” by now.

Johnny wants to branch out and lead his own band. He wants Delia to sing for it. And he’s not keen on her professional and personal rebuffs, so much so that he sets a plot in motion to wreck the marriage and tie her to horn player Cass (Keith Hamilton), at least in the eyes of Rex.

Johnny also has to stir up problems with Cass and his girl (María Velasco, giving an edge to the film’s second interracial couple), cajole Cass into falling off the wagon, as far as “funny” cigarettes go, and make use of Rod’s in-house tape recording system among his many machinations to break this marriage/band apart and get his own launched.

How far will things go?

Harris gives a performance that takes some of the racial stereotyping out of Shakespeare’s “Moor,” a tad too subdued to suggest a man of mercurial moods and capable of violence.

And the finale “modernizes” the climax to “Othello” in ways that suggest Civil Rights era sensitivities that rob the production of much of the pathos and tragedy of the play.

But there is far too much good going on here to discount this film for those failings. A heated debate about the philosophical nature of music almost turns violent, as quoting someone who claimed that “jazz is appreciated by three groups — Negroes, adolescents (pre Beatles, Motown, etc) and intellectuals” and its implied “Which are you?” was fighting words.

Rex questioning his wife’s joining his “alien world” isn’t referring to jazz. It’s about her marrying a Black man. Johnny’s teasing all that “Rex wouldn’t refuse Delia tonight even if she asked him to move to Johannesburg!”was pretty cutting edge in the UK of ’62.

There’s a lot going on here, even if you’re not a jazz buff. And almost all of it spins around McGoohan, his eyes mostly hooded shadows, his smirk Iago-incarnate. Betsy Blair of “Marty” plays Johnny’s long-suffering wife, and alert viewers will spy an unbilled dancer Geoffrey Holder, as himself, a dancer-guest at the party.

So you’ve got the only actor to turn down playing James Bond twice, and “The Saint” as well, co-starring with a future Bond villain (“Live and Let Die”). Cute.

A recent British Film Institute restoration of “All Night Long” makes the visuals shimmer and the music pulse and pound through a dynamic range uncommon for that era of film. Whatever its shortcomings, the performances archived here — jazzmen and McGoohan — make “All Night Long” a classic you’ll want to remember to catch, even if you think “Lionel Ritchie” every time you hear the title.

Rating: “approved,” violence, drug content

Cast: Patrick McGoohan, Paul Harris, Marti Stevens, Keith Mitchell, María Velasco, Richard Attenborough, Charles Mingus, John Dankworth and Dave Brubeck.

Credits: Directed by Basil Dearden, scripted by Nel King and Paul Jarrico, based on “Othello” by Wm. Shakespeare. A Rank Org. release/BFI restoration on Tubi, Amazon, et al.

Running time: 1:31