Nixon in China, Metropolitan Opera HD Live

Metcentric New Yorkers tend to think an opera hasn’t achieved classic status until it arrives at their vast inner sanctum. Whereas other cities worldwide know that the inimitable Peter Sellars production of grand opera’s last masterpiece (to date) has become a virtual brand since its 1987 Houston premiere. John Adams's first, and biggest, opera was an obvious here-to-stay triumph at the Edinburgh Festival the following year, and its strengths become more apparent with the passing of time.

Not that the picture (dark) or the sound (fitful) at Notting Hill's Gate Picturehouse were much to write home about: I've seen brighter, sharper Met transmissions over the years the company has been broadcasting to the world. The question now is, which Nixon will make it to DVD - this one, with only one major drawback I'll discuss shortly, or the televising of the Houston original? That had the virtue of more news footage of the original events inserted between the acts. Otherwise, the Met's presentation is slick to a fault - baritone Thomas Hampson anchors the interviews like a slightly stiff elder statesman contrasting with the likes of naughty schoolboy Sellars, the loveable Mark Morris and Adams himself in cartoon confusion about what to do with his microphone before taking up the baton again - and the interval timings are immaculate.

Sellars, like the great Harry Kupfer, is an opera director who likes to supervise his composition on film, giving his own special version of Adrianne Lobel's well-wearing sets, here newly expanded for the Met, and Dunya Ramicova's costumes. So right from the first expectant crowd scene at Beijing airfield, where the music threatens Minimalism but soon dissolves it in the first of many chameleonic shifts, we got the faces as he wanted them, riveting close-ups on the Chinese members of the cast yielding to all sorts in the Met chorus, as if the momentous lines of Alice Goodman's pure poetry, "the people are the heroes now", might apply to everyone. And indeed the significance of the transmission on the day following the Egyptian crowd's more amiable revolution did not pass unnoticed by Sellars in interview.

Scenes and lines continue to resonate: the future of China and its uneasy relations with capitalism, the sending-back to America of unknown soldiers from campaigns abroad, the mushrooming of the media. Had anything got embalmed since 1987? Possibly the old cold warrior Nixon of James Maddalena, who shouldn't really still have been singing the part even a couple of years ago at English National Opera and who now looks more like Brezhnev in his coffin, despatching what should be his racy first "news" monologue - think Boris Godunov on adrenalin - as well as his exhilarated toast on his first night in Beijing with a kind of rigid terror. But so many of us love him for what he was, Dick to the life, that we wanted him to get through it and found something to be thankful for in the paranoia of his later scenes.

Time, then, for the role to pass to a new baritone - and who better than Russell Braun (pictured above right in the Act One finale), the one fresh revelation in the cast, catching all the dignity and honour of Chou En-lai in his big banquet speech and all the pathos of his final post-mortem ("How much of what we did was good?"), yielding to tentative hope as the exquisite solo strings of the superb Met Orchestra did the best of all possible jobs on their rising figures at the end.

One thing that's become abundantly clear is how fabulously structured is Adams's whole. In Act One, the portraits of the men take us from Nixon's euphoria to Mao's enigmatic utterances - philosophy or senility, speculated an old Nixon adviser in an interval interview, hard to tell, but superbly done in heroic high-tenor declamation by the stalwart and seemingly tireless Robert Brubaker - and over to Chou. Act Two belongs to the women. First there's Pat's wonderment at an ambiguous brave new world, one of the great opera arias of the 20th century with Adams's incredible word-setting well matched to Goodman's metaphysical poetry ("Let the expression on the face/ Of the Statue of Liberty/ Change just a little; let her see/ What lies inland"). Carolann Page was fine on the premiere recording, but the part now belongs to Janis Kelly (pictured above left): another longterm operatic warrior perfectly in control both of her dangerously high-lying phrases and of her utterly believable characterisation.

Adams then does a Don Carlos and moves us from private to public. Madame Mao's Gone with the Wind-inspired Red Army ballet still amuses and chills in dizzying turn: Morris has kept the dancers and their high kicks fresh, the trio of impassive Maoettes redeems a slightly woolly female chorus, Richard Paul Fink lets rip with the surreal eruption of Kissinger as capitalist villain and at last we get to hear the Met brass at full pelt - Adams the conductor seems to be relishing this - culminating in Chiang-Ch'ing's coloratura reign of terror. ENO's Judith Howarth still holds the steely palm, but the vowel-moderated delivery of Kathleen Kim (pictured right) was not without its knife-edge, paintstripping overtones.

I love the heartbreak of the last act best, and its polyphonic chamber music is ideal for the close-ups of this screening (especially as Sellars still, I think, somewhat jumbles up the stage with references to what's been and what's to come which can be confusing). This is the private fall-out and exhaustion of the leading players, all masks removed; and again, in the what-next twilight following the fall of Mubarak, its open-ended questions have a special resonance. Sellars makes sure each act virtually freeze frames on a snapshot: of Nixon united with Chou in Act One, Madame Mao versus Chou in Act Two and Chou alone, awaiting his death but also possibly the dawn of hope before the blackout. "The chill of grace/ Lies heavy on the morning grass" is the line he leaves us with as Adams's score does a transcendental riff on Holst's Neptune. What a perfect ending to the only post-Britten opera sure of a key place in the repertoire.

Watch a scene from the original Chinese Red Detachment of Women ballet

• Next Met Live screening is Gluck's Iphigénie en Tauride with Susan Graham and Placido Domingo on 26 February
• Find the premiere recording of Nixon in China on Amazon
• Hear Marin Alsop conduct the London Philharmonic Orchestra in Adams's Doctor Atomic Symphony at the Southbank in March