Every summer, Mannes College offers its Beethoven Institute, a weeklong flurry of classes, lectures, and concerts. The 2006 version finished up yesterday, with student performances. But on Friday night, there was a faculty concert, whose program was all-Beethoven (as expected). We’ve certainly had a lot of him this year, what with that 250th anniversary.

(Just kidding – as you know, that’s the younger, white-wigged, Salzburgborn one.)

Friday night’s program was not just random; it had a theme. And that theme was variations. In his program notes, Thomas Sauer, a pianist and director of the Beethoven Institute, wrote the following: “Beethoven composed variations sets throughout his career, aiming aesthetically high (Ninth Symphony slow movement), low (Variations on ‘Rule Britannia’), and in between (the sets on tonight’s program).”

That program consisted of two pieces for solo piano and two piano trios.

And it began with Fourteen Variations for Piano Trio in E flat, Op. 44.As Mr. Sauer remarked from the stage, this is a little-known work – “and Beethoven wasn’t a composer of little-known works; he was a composer of well-known works.” No matter what its fame, Op. 44 is Beethoven, and a delight.

Playing this trio were Mr. Sauer, the violinist Mark Steinberg, and the cellist Michael Kannen. Mr. Steinberg is first violinist of the Brentano String Quartet, and Mr. Kannen was once cellist of that same quartet. Beethoven’s work started promisingly: with detached notes together, intense, and stylish. And the performance largely lived up to this opening.

Mr. Steinberg did not contribute his best sound, but he was never offensive. In Mr. Kannen’s sound was an appealing darkness, and he evinced an excellent sense of rhythm. The pianist, Mr. Sauer, played solidly and intelligently – also a bit stiffly at times, and this stiffness was evident in (for example) trills.

Beethoven varies the mood of his set more than our three players did. I would have liked a touch more humor, and more slyness, and more abandon. But the three were thoroughly competent, and made a sure case for Op. 44.

Then Mr. Sauer took the stage alone, for one of Beethoven’s best piano sonatas (though, in truth, all 32 are among Beethoven’s “best”). This one was the Sonata in A flat, Op. 26, which begins with a set of variations. Then it has a marvelous scherzo, followed by one of Beethoven’s funeral marches – superb, of course. And it closes with an absolutely wonderful, winsome Allegro.

Mr. Sauer was, again, solid, and, again, a bit stiff. In those variations, he could have shown us a better sense of line. As it was, he played some odd accents, sometimes knocking a phrase out of shape. The scherzo was suitable in character,though a bit heavy. The funeral march could have embodied more resolution – but Mr. Sauer handled some of the soft passages beautifully.

And that wonderful, winsome finale? Mr. Sauer played it fairly gracefully, although he might have lent more of a sparkle, more elan. Few pieces are as enjoyable as this little number.

Following the sonata was a piano work so little known, it verges on the unknown: Six Variations on an Original Theme, Op. 34. It is not as good a piece as the sonata, but, again – this is Beethoven. On hand to play Op. 34 was Robert McDonald, best known to the world as the regular accompanist of Midori (the one-named violinist). (Mr. Sauer sometimes plays for her too.) Mr. McDonald is an admirable musician in his own right, once the winner of the Busoni Competition, among others.

He is a precise, thoughtful, unsilly pianist, and so he proved on Friday night. Op. 34 begins simply, and Mr. McDonald was duly simple – in balance, unforced, lyrical. Later, some of his passagework was effortful, which was surprising. But he was, on the whole, crisp and alert. Beethoven requires alertness from those who play him – more than the average composer, I think – and Mr. McDonald provides a lot of it.

The set, incidentally, ended with some of the same simplicity with which it had begun.

After intermission, it was piano-trio time again, and we returned to that key of E flat. The work was Op. 70, No. 2, and it is loved the world over. Why wouldn’t it be? Mr. McDonald was the pianist, and he was joined by two – two more – members of the Brentano String Quartet. These were Serena Canin, violin, and Nina Lee, cello. (The very name of their quartet has a Beethoven connection, as the composer’s “immortal beloved” is thought to be one Antonie Brentano.)

This trio, Op. 70, No. 2, is typical Beethoven, combining beauty and strength. The three players gave us those qualities, and any others that Beethoven calls for. This was a performance that was so sound, you could sort of forget the playing: You could concentrate on the music. The second movement, Allegretto, was particularly good: It exhibited Beethoven’s poetic virility (if I may). And the third movement, Allegretto ma non troppo, carried its unhurried, quiet power.

The final movement was not so good: less cohesive, more mistake-prone, less convincing than the others. But it still scored, really, as did Beethoven, all evening long. Somebody ought to dedicate an institute to him.