At age 81, Alvin Epstein is an actor from whom one can reliably expect great things. Case in point: his performance earlier this summer in the Actors’ Shakespeare Project’s production of “King Lear” at La MaMa. What Mr. Epstein brought to the stage was a sensibility — culled from a 60-year career in the theater — that gave him freedom to create what was essentially a new King Lear. It was truly avant-garde Shakespeare, and it was true to Shakespeare.

“The opportunity itself to do King Lear is special,” Mr. Epstein said. “Aside from Hamlet, and maybe even more so than Hamlet, the biggest hurdle that an actor can put up in front of himself is to play the king. An old saw about Lear is that to play him you have to be old enough to understand him, and by that time you’re too old to do it.You haven’t the physical stamina.”

Such thinking, however, was thoroughly disproved at La MaMa. Mr. Epstein created the feeling that he did not embody Lear, but he went beyond. In a way, he disembodied Lear. Lear as Epstein as Lear.

A performance of this caliber doesn’t come along often.Which makes it worth asking: What are the advantages of age onstage? What does an octogenarian bring to the stage that a matinee idol cannot? In part, the answer is easy: Experience. Cast in the premiers of Samuel Beckett’s “Waiting for Godot” in 1956 and “Endgame” 1958, Mr. Epstein has, simply put, been around. He served as the artistic director of the Guthrie Theatre in Minneapolis. Between the late 1960s and 2004, he acted, directed, and taught at the Yale Repertory Theatre, and then at the American Repertory Theatre at Harvard, in addition to creating roles on Broadway and off.

But how did that experience manifest itself in Mr. Epstein’s Lear? What understandings did he draw on to yield such a rich, textured treatment of this 400-year-old play? The answers are not to be found in Cliffs Notes.

For many years, Mr. Epstein did not care much for “King Lear.” “The play has become like the hull of a very old ship covered with barnacles,” he said. “You don’t see the hull anymore — only the barnacles: accumulated, predigested ideas, among them a star turn for a big ego and a bellowing voice. In Shakespeare’s time it was a brand new play. No traditions had grown around it yet.”

Mr. Epstein knows from Lear tradition. He has played the Fool opposite Orson Welles as the king and Gloucester opposite F. Murray Abraham in the title role. He also played the Fool in Hebrew with Habima, the national theater of Israel, in the early 1950s.

In order to break away from those traditions, the actor imagined what the play was like when Shakespeare wrote it. Quick with ferocious action, the work overflows with meaning on emotional, familial, political, and mythical levels. But, Mr. Epstein argues that “Lear” wasn’t written about a monumental figure.

“It was written about a real old man. The play is mythological in scope through the role’s completeness, but domestic in its constant connection to truth,” he said. “Shakespeare had a piercing knowledge of human nature: The play is about real people, with faults, riddled with doubts. Lear makes a terrible mistake and pays the price.”

Describing Shakespeare’s language, Mr. Epstein sheds light on what characterizes his own approach to theater: “The intense compression of ideas and emotions into very shapely and short phrases that travel like music. How can I put this big thought into as tight a little box as I can — say the most with the least amount of words?”

His approach is akin to what Beckett did in creating his works; he pared away all the extra. Mr. Epstein accomplishes this through an instinct for clarity, in the elicitation of a word, the crook of one finger, a bend of the neck, the tilt of the upper torso — movement emphasized and specific but also looking utterly natural; never overdone or underdone.

During his performance, the actor physically showed Lear’s deteriorating state of mind in his gradual languishing of stature throughout the play. From an erect king savoring his last moments of power, he becomes a crumpled, exasperated, thwarted father. From that, he devolves into a physically and mentally failing, but manically agile, figure who darts back and forth clad only in a diaper. He presses on, as a dying Pieta-like wraith and then to the horizontal stillness of death.

Mr. Epstein’s ability to execute this approach comes from a lifetime of work. When he started acting, he had in mind for himself a “completely different path” from the standard, naturalistic mid-century theater style. Strongly influenced by Edward Gordon Craig, the abstractionist theater innovator of the first half of the 20th century, Mr. Epstein spent a year working with master choreographer Martha Graham, whom he admired for her “theatrical vision.” Her new language of movements that explored the capability of the body to visually express psychological states drew him to her technique.

His New York debut in 1955 was as a mime, with the great Marcel Marceau (who had been Mr. Epstein’s classmate in the famed mime school of Etienne Decroux in Paris in the late 1940s). He went on to play, in that same season, the Fool in Welles’s “Lear,” and Lucky, the slave, in “Godot,” both roles that demanded very physical, visual interpretations.

But the connections between Mr. Epstein, Beckett, and Shakespeare are not confined to a stringent attitude toward physicality. Mr. Epstein added, “the similarity of Shakespeare’s view of humanity to Beckett’s is evident in Lear’s words when he ends up on the heath in a storm, decrying the human condition:

Poor naked wretches… That bide the pelting of this pitiless storm, How shall your houseless heads and unfed sides, …defend you From seasons such as these?”

“And later, ‘Unaccommodated man is no more but such a poor, bare, forked Animal,'” Mr. Epstein said, adding that these are “phrases that also bring to mind the emaciated figures sculpted by Alberto Giacometti, Beckett’s friend.This scene is where the self-realization occurs in Lear. Exposed to the indifferent cruelty of nature, Lear discovers the humanity he shares with other ‘poor naked wretches.’ This from a raving, spoiled tyrant. What a change, what a turnaround of character!”

As a further example of this make-or-break moment in the play, he continued to recite, with obvious pleasure and without breaking the momentum in conversation,

…Oh I have ta’en
Too little care of this. Take physic, pomp,
Expose thyself to feel what wretches feel,
That thou may’st shake the superflux to them
And show the heavens more just.

These extraordinary passages during the storm on the heath are what Mr. Epstein calls “the most difficult scene for an actor.” The words are precise and, in the way of poetry, sufficient in themselves, challenging the actor even to utter them. “But very often the approach to it is stentorian: Just bellow the words. Again, a culturally approved misunderstanding of the play,” Mr. Epstein said. “And you can’t drown out Shakespeare’s words with sound effects. The actor is the heart of it. He has to bring it off by invoking both the storm that is in his head and the terrific deluge that cannot be really happening on the stage.”

And how does he accomplish this? “That’s the mystery of acting.You can’t explain everything. Lear is not actually describing the storm; he is summoning nature to do nothing less than destroy the world and all the people in it,”

Blow, winds, and crack your cheeks!
Rage, blow….
Strike flat the thick rotundity o’ th’ world,
Crack nature’s molds…
That makes ingrateful man.

With language so magnificent and a character so complicated, the challenge of taking on this role was transformative.”During the run in Boston and New York, I became aware that this play had become so meaningful to me that the idea that I was performing actions and speaking words written by somebody named William Shakespeare seemed absurd,” Mr. Epstein said, adding that the words seemed like his own. “My thoughts and my responses. Not that I was going mad, like the king, but the simulating of those things seemed to be coming from me spontaneously.”

Is this what convincing acting should be? “Perhaps.The language has begun to feel so normal to me that it’s not Shakespearean speech. It’s the language of today, it’s the language of what is happening right now.”

Mr. Epstein will next perform an experimental program under the title “Who’s Your Dada?” with the Wooster Group at the Museum of Modern Art on September 6, 7, and 9.