Leon Botstein is music director of the American Symphony Orchestra, and he doesn’t put on conventional programs. He puts on unconventional ones. And so it was on Sunday afternoon, at Avery Fisher Hall.

The program was called “From Russia With Mozart,” and here’s the reason for that curious title: Mr. Botstein and his forces presented two one-act operas by Russians, both with a Mozart theme, or connection. In 1897, Rimsky-Korsakov composed “Mozart and Salieri,” on a Pushkin text. You remember Peter Shaffer’s fantasy, “Amadeus,” from 20 years ago? Same (basic) deal. And in 1869, Alexander Dargomizhsky had composed “The Stone Guest,” on another Pushkin text – treating the Don Juan legend (which Mozart made use of, one hears).

This was a fascinating afternoon of music-making, and music discovery. It certainly helped that the singing was first-rate.

Rimsky-Korsakov’s one-act opera is also a two-man opera – which is to say, there are two singers in it, a tenor and a bass (or baritone). Salieri, being bad, is sung by the low voice, and Mozart, being good – or at least innocent – is sung by the tenor. Rimsky-Korsakov’s piece is skillful, quoting Mozart’s oeuvre from time to time.

Mr. Botstein and the ASO employed two crackerjack singers from Russia, one of whom was a substitute. The American Richard Paul Fink was slated to sing Salieri. But, indisposed for a reason not given, he was replaced by Andrei Antonov, who was superb: His sound was rich and regal, almost wet; and his technique was rock-solid. As Salieri, he was appropriately brooding and wracked, but not overemotional.

The tenor singing Mozart – that is, the role of Mozart! – was Leonid Zakhozhaev, a star of the Kirov Opera. He ought to be a star here, really. According to his bio, he sings both Tristan and Tamino (in Mozart’s “Magic Flute”). I’m not sure I’d ever heard of a tenor who sings both of these tremendously diverse roles, plus Siegfried, Faust, and others.

On Sunday afternoon, Mr. Zakhozhaev’s singing was clear, beautiful, and utterly unforced. When he got loud, he didn’t strain, which was strange.Tenors are supposed to strain, or strangle, or be strangled. Mr. Zakhozhaev could find himself kicked out of the tenors’ union.

And, like Mr. Antonov, he portrayed his character intelligently and compellingly, with no overacting. It’s hard to know how much acting to do in concert opera (and perhaps in opera itself, come to think of it). Messrs. Zakhozhaev and Antonov both knew.

From the American Symphony Orchestra, there was much good playing, individually and collectively. As for Mr. Botstein, he is a conductor whom critics like to take shots at (imagine). The president of Bard College and an all-purpose intellectual, he is not a conductor of the first rank. But look: He makes fewer errors, and causes less exasperation, than many conductors who are acclaimed.

And by the way, the New York Philharmonic, when it performs vocal works, uses supertitles, in this Avery Fisher Hall. Could not the ASO have done the same? (They passed out librettos.) I suspect that the relevant union would have extracted a small fortune, or a large one, for such a service. It’s amazing that the lights get turned on (and off).

Rimsky-Korsakov and others revered the older composer, Dargomizhsky, and it was R-K, along with Cesar Cui, who finished “The Stone Guest,” incomplete on the composer’s death.

The story of this opera, of course, will be familiar, from “Don Giovanni.” But there are important and interesting differences. For example, Dona Ana is the Commander’s wife (and then widow), not his daughter. And, story aside, Don Juan’s a tenor, not a baritone (or bass)! Tenors would surely appreciate the main role in Mozart’s show.

You may ask about the quality of Dargomizhsky’s score. In brief, it may not be immortal – but it is certainly worth knowing (as is that composer’s output as a whole).

Mr. Zakhozhaev was our Don Juan, all Joe Cool in his open collar. Again, he would be a star in America, with the right marketing. If we can learn to pronounce “Hvorostovsky” – as in the baritone Dmitri – we can learn to pronounce “Zakhozhaev.” And Andrei Antonov was Leporello, the Don’s servant and sidekick. Mr. Antonov suffered a touch of bad intonation in this opera, but was otherwise his rich, canny self.

Singing the role of Dona Ana was the soprano Marina Shaguch, of a darkish, intriguing, penetrating voice. She issued a kind of dark laser of sound. And her singing was formidable in other respects, as well. A mezzosoprano, Stephanie Novacek, sang Laura. (Who she? Just another of Don Juan’s strangely faithful, strangely smitten girls.) She began somewhat muffled – the voice seeming to be in the back of the throat – but she improved as the opera wore on. And her flair for drama was obvious.

The baritone David Adam Moore was Don Carlos (Laura’s lover-for-amoment, slain by Don Juan). Mr. Moore was smooth and sturdy enough. A bass, Daniel Okulitch, sang the Monk (yes, the Monk), and, rather like Ms. Novacek, he tended to swallow his sound. But he got his points across. Mr. Okulitch happened to return at the end of the opera, for the few lines of the Commander, the Stone Guest.

And, speaking of guests, Michael Lee sang a role called the First Guest. In it, he showed off a bright, appealing tenor.

Under Mr. Botstein’s baton, the score could have been more vivid, more exciting – in the climaxes, for example – but he made his case, amply. And I might say that, more than “Mozart and Salieri” – which is a psychological opera – “The Stone Guest” cries out to be seen, as well as heard. Perhaps we will have a full-out production one day.

In the meantime, Mr. Botstein has, again, performed a service.