With its exhilarating changes in register, its elusive journeys, ambitious vocabulary and, more than anything else, its intoxicating sense of fun, there's a renewed vigour to this latest offering from one of America's most accomplished poets. Here we have 63 entertaining, often comic, poems that relish the open play of language, the bravado of a tongue-in-cheek dancing on the edge ("we wove closer to the abyss, a maze of sunflowers. The dauphin said to take our time").

Quick Question is dedicated to the painter Jane Freilicher, a testament to Ashbery's long-standing friendship with her stretching back to a close-knit group of artists and poets in early 50s New York. It was out of this coterie that a new sensibility arrived in American poetry, an enticing mixture of the comic and flamboyant. Ashbery has said that at Harvard in the late 40s he first realised that "nothing was too silly to bother with", that fun and high camp were worthy poetic goals. Sixty four years later, he's delivering perfectly pitched spins on this heady combination  "She was startling in her new headdress./ Oodles of trolls performed the funeral litany."

The new book, at times, offers glimpses into his early enthusiasm for the ornate, rarefied worlds of the English novelist Ronald Firbank  "The caveats, God help 'em, were by this time so deep/ in denial the servants never saw them again,/ or realised they were missing." And the outrageous is never far away  "He came like the Johnstown flood./ It was worth waiting for."

But Ashbery's poems are remarkably flexible and supple, evoking a much wider range of tones and possibilities. "Silent Auction" moves from camp to something more ominous, especially through its reworking of "Twas the night before Christmas"  "Wow, kitty, that sure/ looked real, you've got to admit, and I in my wrapper// and Mama in her cap put out stories about the new/ mood that slurped above the horizon." Playing with quotations, stock phrases and nursery rhymes is a device he employs throughout  "Everywhere that Mary went/ dynasties collapsed amid gnashing of teeth."

Pieces such as "Card of Thanks" display Ashbery's very different penchant for mystery and melodrama, a nod towards his recent translation of Rimbaud's Illuminations with its venomous declarative sweep  "O it seemed subtle, whatever was hissing/ like a vulture over the town. You're going to feel well,/ giants of rhetoric, devastating in the now."

But there are also more direct and moving poems here. "This Economy" is an outstanding piece of writing. It begins with a playful moment of empathy  "In all my years as a pedestrian/ serving juice to guests, it never occurred to me/ thoughtfully to imagine how a radish feels." Yet this quickly transforms into a lyric quietly addressing the problem of seeing into others' lives. New figures hover on the periphery as the poem portrays a miniature history of the US  "how we elaborated/ ourselves staggering across tracts". It then takes up a repeated phrase, echoing the technique of listing people and situations that Whitman employed to suggest the vastness and epic sense of the States: "Somewhere in America there is a naked person.// Somewhere in America adoring legions blush/ in the sunset "

The language here moves from the intimate to the cinematic, before Ashbery delivers an image in which the poem itself becomes a commodity and steps into the landscape  "Somewhere in America someone is trying to figure out/ how to pay for this." It's very much a lyric of the moment, tentatively exploring how nations perceive themselves and each other as financial structures, and the countless small-scale decisions that make up such systems. The poem continues, carried forward by the impulse to open further doors, to let in more light  "Somewhere/ in America the lonely enchanted eye each other/ on a bus."

This gift for constantly shifting register and scale sustains the collection as a whole. Everything remains invigoratingly at sea  "whatever stops playing is the enemy of the incomplete". The final poems of Quick Question play games, however, not only with the inevitable completion of the book, but also raise the issue of Ashbery's entire career. He is now 85 and has been steadily publishing since Turandot and Other Poems in 1953. The penultimate lyric "Postlude and Prequel" (the title perfectly embodies Ashbery's desire to keep things open, to have his cake and eat it) is about a long-standing friendship, like Ashbery's with Freilicher  "with long awaited words from back when we were/ friends and still are, of course".

It is a poem brimming with everyday life, the ordinary details of urban New York  the availability of tickets for an event, heavy traffic, the benches of Central Park. But it is also a work about fragility, about being under threat, surrounded by hints of finality and loss  "Perturbing elements/ listen in the wings, which are coming apart at the seams."

Yet, in the end, the collection is dominated by surprise and energy; the wonderful opening of "A Voice from the Fireplace" ("Like a windup denture in a joke store/ fate approaches"); the delighted onrush of "Bacon Grabbers" and "Saps at Sea"; the rich textures of "Suburban Burma" that deliver a typically wayward invitation difficult to resist  "Don't try this at home. On second thought, come in,/ your tumbling face ungladden. And see what happens."