Evgeny Kissin performed little-known works by Jewish composers and recited poetry in Yiddish at the Kennedy Center Concert Hall on Monday. (Felix Broede)

One of the points of attending a live performance is to watch artists express themselves. Yet the concert hall experience has become codified in traditions that affect everything from how we dress to what we see onstage. Many artists have challenged these traditions, and to them, we tend to assign labels such as “experimental” or “avant-garde.”

But it almost never happens that a superstar gets up in his established context and does something completely different, without intending any challenge to the status quo at all, but simply to express something that is in his heart.

Evgeny Kissin, the pianist, did this — breathtakingly — at the Kennedy Center Concert Hall on Monday night.

First, he played music that almost nobody in the audience had ever heard. The concert was a co-production of the Kennedy Center and Pro Musica Hebraica, the organization founded by Charles Krauthammer and his wife, Robyn, to help bring Jewish music to the concert stage. Kissin, who in December took Israeli citizenship in a striking gesture of affirmation of his heritage, played mainly works by Russian Jewish composers of the early 20th century. They were Moyshe Milner, whose “Farn opsheyd” (“Before Separation”) was an intricate, acerbic rhapsody on a Jewish folk song; Alexander Veprik, represented by a powerful second sonata; and Alexander Krein, whose “Suite dansée” offered klezmer tunes through a nominally Baroque filter, though even some of the light-hearted movements (Kissin played five of the original six) darkened considerably before they were done. The fourth piece was not exactly standard concert fare, either: Ernest Bloch’s piano sonata, rich and intense and railing at the keyboard until it finally seemed simply to throw up its hands and give up.

Second, Kissin recited poetry. In Yiddish.

On paper, this threatened to take the proceedings into the realm of the downright eccentric. Poetry readings are a specialized taste and are hard enough for trained actors to pull off. And Kissin has never given the impression of being a particularly expressive verbal communicator, generally restricting his onstage remarks to shouting the names of his encores.

So when he got up from the piano and began declaiming Haim Nachman Bialik’s “High on a Mountain” with the authority and linguistic assurance and expression of someone who has been reciting to crowds all his life (as supertitles over his head let the audience know what he was saying), there was a palpable sense in the auditorium, for the space of one held breath, of an invisible membrane of preconceptions popping silently, like a soap bubble.

That Kissin is a brilliant piano player is not news. By the time he got to his first poetry segment, he had presented the Milner with a sophisticated clarity, the viscous transparency of a dry cocktail, and wrung the Bloch into something approaching monumentality. It was not surprising that he mined the expressive power of the Veprik and danced serenely along with the Krein. None of these are easy works; all are worth more hearings, especially if they’re played like this.

But that he is a brilliant stage animal in every respect; that he could appear to have stepped into another character and be channeling some fictive Yiddish literary eminence, down to the inflections and the physical gestures; that he could savor and convey the words and emotions of a written text as he does the notes of a printed score, was not something I, at least, had suspected. Which is a failure of my own imagination, since reason would dictate that Kissin, with a lifetime of stage experience, would not take such a risk if he didn’t know he could pull it off.

Music is intimate, but in our ornate concert halls, we sometimes forget it. Poetry is more intimate, and less often encountered in a 2,000-seat-hall. To hear both together, offered without pretension but with the simple directness of an open heart, linked everyone in the hall on a shared journey into the past; even for those of us who do not have memories of Yiddish-speaking grandparents, Kissin was a living embodiment of a bygone world. It also helped link the works into the larger context of the Western canon from which they are marginalized, pointing out the connections between Milner and Scriabin, or Isaac Leybush Peretz, the other poet on the program, and Paul Celan, one of the greatest of German-language poets, who also spoke Yiddish, and whose greatest work echoes some of the same verbal patterns audible in Peretz’s “The World Is a Theater” or “Don’t Think.”

When we speak of virtuosity, we generally mean technical ability. It takes a different kind of virtuosity to play four musical pieces and declaim 13 poems in Yiddish (including the encore, “The Joy of the Yiddish Word” by Yankev Glatshteyn) entirely from memory, all with equal mastery. I wish that Kissin were creating a new world of possibilities for all star performers, but I’m not sure anyone else has the virtuosity to step this far outside the box with such honesty and dignity and power. I also wish this concert had been recorded. As it is, it is an evening I will remember all my life.