What is that man of mature vintage thinking as he sits in the stark rectangle of light, staring out at us with those wistful, hooded eyes? The miracle of superlative acting is that an audience can be held, and fully stirred, by a gesture as gentle and neutral as a far-off gaze.

In his definitive turn as the brooding, coughing Krapp of Samuel Beckett’s absurdist classic “Krapp’s Last Tape,” John Hurt invites you to wonder anew at the solitary figure who listens to a recording of his own voice from a night long ago, and in that act expresses the tragicomic weight of time passing, body disintegrating and love receding.

You’d imagine that an actor engaged in the existential Kabuki of Beckett, meticulously enacting the rituals of this half-century-old one-act play, might afflict us with a sense of a road slowly traveled.

Quite the contrary occurs in the Lansburgh Theatre, where the Shakespeare Theatre Company is presenting the piece through Sunday, before it moves on to a limited run in New York. “Krapp’s Last Tape,” directed with crackling intelligence by the Gate Theatre of Dublin’s Michael Colgan, seems to whiz by in 55 keenly observed minutes.

As an actor, the 71-year-old Hurt is not so much unsung as under-sung; maybe it’s because he rarely repeats himself (except in a small recurring role in the “Harry Potter” movies) and gravitates toward the offbeat. Have you ever seen his heart-piercingly dignified Quentin Crisp in the 1975 “The Naked Civil Servant”? Or his crazily serene Caligula in the “I, Claudius” mini-series of the same era? You no doubt could add your own favorites to this catalogue. As it turns out, Hurt’s exquisite capabilities resound, too, on a stage. Here, he proves himself to be a maestro of stillness.

As with “The Tempest,” “Krapp’s Last Tape” seems an ever more meaningful statement as a spectator gets older. It’s not until your own joints begin to ache that you can really appreciate the agonized choreography of Krapp’s shuffling (in risibly squeaky shoes) from his desk piled high with reels of tape to the cabinet offstage where he cushions the blows of memory with drink.

And memory for Krapp is not a cluttered shelf in his consciousness. It’s an electronic archive of his lyrical musings, recorded over the decades; as a result, they stay forever retrievable. “Box three . . . spool five . . . ” he intones, cross-checking in a thick, dusty account book for the spot in the narrative of his life he’s about to revisit. “Farewell to . . . love,” he reads, as he turns the page and presses a button on the old reel-to-reel. Soon, we’re listening to Hurt’s Krapp in a voice from 30 years earlier, describing a carnal interlude with a lover.

You’re compelled to wonder: Is it a recollection he fast-forwards to often? Is it entertainment or penance? Does the replaying relieve loneliness? Or intensify it?

We monitor the incremental changes in Hurt’s expression — a minor adjustment of his eyebrows, the slightest upturning of his chin — for clues as to what this means to the old man. Occasionally, the actor pauses and glances over his shoulder, as if Krapp is afraid someone is there. Or, more to the point, perhaps he wishes someone were.

Is there a gene for watchability? Hurt has an instinct for just how much emotion needs to register on his features. (And with his lean, sallow countenance and thick, cropped hair, he looks uncannily like the playwright.)

As Krapp becomes more agitated and absorbed by the narration, Hurt enfolds the tape recorder in his arms, as if his impulse were to protect it. An audience seeks to envelop this actor in an embrace of comparable appreciation.

Krapp’s Last Tape

by Samuel Beckett. Directed by Michael Colgan. Lighting, James McConnell. About 55 minutes. Through Sunday at Lansburgh Theatre, 450 Seventh St. NW. Visit www.shakespearetheatre.org or call 202-547-1122.