There’s a good bit of virtuoso hamming going on right now at Studio Theatre, but the most succinctly dazzling moment might be when the venerable Paxton Whitehead, offhandedly but with absolute authority, responds to a puzzled query from a character who thinks he’s done his homework. The answer involves a bit of first-hand fact-sourcing, and it might involve six words—seven, max. Whitehead delivers them, walking purposefully across the stage on his way to tend to something else, with a turn of the head and a suggestive lean on the word “read.” Though he never breaks stride, the penny drops definitively, and when it does it sets about three layers of hilarity spinning. It’s delightful, both as a writerly curveball and as an actorly home run, and it’s only a tiny part of what makes The Habit of Art such a singularly inside-baseball pleasure.

Whitehead’s character is himself an actor, you see, and the man with the question is both a playwright and the object of some exasperation. The scene is a rehearsal room at England’s National Theatre, where the two of them (along with sordid others) are fitfully putting the final touches on a seemingly troubled new play about the poet W.H. Auden and the composer Benjamin Britten in the twilight of their lives. Now, if there’s anything a theater audience loves more than a glimpse at the foibles of artists, it would have to be a glimpse at the foibles of artists putting on a drama about the foibles of artists. And if it’s set at one of the world’s theatrical meccas? Grand slam!

Alan Bennett’s warm, generous comedy isn’t quite as calculated as I’ve made it sound, but then of course you’d expect more from the author of The History Boys and the man behind the sometimes tart, sometimes trenchant shorts that make up the BBC series Talking Heads. This play-in-a-play is at once a meditation on the rigors of staying relevant as one of the Aging Anointed—no coincidence that Bennett, at 77, has already outlived both of his great-artist subjects—and an inquiry into the sources of creative transcendence. Can a writer with bad taste still know something profound about a character? Can fine actors still do good work if the lines occasionally go clunk? If an acknowledged genius disavows an early work, is it necessarily bad? Is the end product the measure of the master, or is his dutiful shouldering of the muse’s yoke—“the habit of art,” as Bennett’s Auden puts it—a kinder metric?

The play is a respectful nod, too, in the direction of just how tedious and terrifying the process of making even half-assed art can be. (How half-assed is the art? Well, the director’s out of town, two cast members are playing a matinee and can’t make the rehearsal, and the playwright has written scenes in which the furniture talks. The furniture. Talks.)

Ted van Griethuysen, lordly and irascible as the forgetful veteran actor playing Auden, and Cameron Folmar, earnest but needy as the junior ensemble player who’s been cast as what’s too obviously an authorial device, make the “terrifying” side of Bennett’s case—the more emotionally affecting side—with efficiency and grace. Margaret Daly, as the stage manager who contains their tantrums with the unconscious effortlessness of an old pro, helps make plain the pain of the “tedious” part. (And comically, too.)

Whitehead—that ambulatory theatrical treasure—is sheer bliss, naughtily funny when he’s just the actor Henry, a mix of mildly defensive pride and agonizing tongue-tied awkwardness as Britten. And there’s nice, unobtrusive work from a surprisingly populous supporting ensemble—call them six characters in search of some business—with a nicely understated Randy Harrison at their head, playing a comely young tyro playing a rent-boy for whom a BBC producer is briefly mistaken. (I know! But it’s a backstage comedy, people, and I only have so much space here.)

The later stretches of Act II do waffle a bit, as if director David Muse (or maybe Bennett, to be frank) hasn’t quite decided whether the play’s really about the actors, or the artists they’re paying homage to, or about the notion that art’s chroniclers should find a way to recognize the handmaidens (hey, that’s why that rent-boy gets so much stage time!) as well as the high priests. Never mind: The Habit of Art is an affectionate, well-turned testament to the makers of art and the people who understand what makes them worthwhile. Only the punters who pay full price would quibble about its imperfections; if you’ve ever waited in line for standby, you’ll have a grand time.