Beware of hyperbole. Words such as ‘masterpiece’ are freely tossed about in the commentary surrounding the Metropolitan Opera debut of Nixon in China, putting an awful weight on a piece that is still gaining a footing in the repertoire. Unlike Peter Grimes, Nixon in China wasn’t a fully realised bolt out of the blue. It stood on the shoulders of Philip Glass’s oratorio-like Satyagraha, though with a more textured narrative that steered the post-minimalist aesthetic closer to the traditional story-telling of mainstream opera. But not until Act 3, with its jaunty echoes of the orchestral work The Chairman Dances and eloquent soliloquies given to each major character, can Nixon in China be mentioned in the same breath as Adams’s far more evolved El Niño and Doctor Atomic.

Until then, it’s a first-effort opera in many ways. Though Adams had written highly characteristic works such as Harmonielehre when Nixon in China was premiered in 1987, he fell back on Glass’s less flexible minimalism even as the libretto strikes out in many theatrical directions – a documentary in the Nixon/Mao meeting, a dreamy Chinese pastorale in Pat Nixon’s tour of the country and a surreal free-for-all in the brutal Red Detachment of Women ballet (choreographed by Mark Morris). In the aria ‘News, news, news, news’, Nixon participates in the scene while narrating it but without music that’s suitably agile to pull it off – or the smokescreen of assumed satirical undercurrent that audiences once brought to the opera.

Now that its subject matter is no longer novel, the opera is more serious. With dark, wintry stage designs by Adrianne Lobel and singers who more readily wrap their voices around Adams’s vocal lines, stage director Peter Sellars draws less physically animated, more earnest, detailed performances. Sympathy for the disgraced president was hard to come by in 1987 but here, James Maddelena (though not in his best voice) portrays a more noble Nixon pushed to his diplomatic limits. The heart of the opera is Pat Nixon, portrayed by Janis Kelly with less sense of submission and a lot more depth. Russell Braun’s Chou En-lai projects vision and intelligence in his voice but shows the world a stern, stone face – except when in pain since, as we now know, he had untreated pancreatic cancer. Was Mao senile or foxy? Robert Brubaker keeps you guessing. The Mao-ettes (a trio of secretaries) are no longer played for laughs. When everybody turns in for the night in the final scene, the beds now become coffins for Chou and Mao. Given Sellars’s penchant for tight camera close-ups in his video direction, the opera often feels like the intimate chamber work that, in its conflicted heart, it actually wants to be.