Christian Tetzlaff, the young German violinist, has been on a bit of a Bartok tear. For Virgin Classics – and with the (excellent) Norwegian pianist Leif Ove Andsnes – he has recorded the complete Bartok sonatas. Those works include the unaccompanied sonata that the composer wrote for Yehudi Menuhin in 1944 (Bartok’s penultimate year). In the most recent subscription series of the New York Philharmonic, Mr. Tetzlaff played Bartok’s Violin Concerto No. 2, which we used to know as the Bartok Violin Concerto, until an earlier effort was discovered and entered into the repertory.

On Friday afternoon, Mr. Tetzlaff gave a great performance. Simply a great performance. You felt you had heard Bartok’s concerto at its height.

Mr. Tetzlaff was extremely well prepared, both technically and mentally. He employed a variety of tones, and that includes a variety of widths. He was both rough and elegant, depending on the interpretive needs of the moment. This mirrored Bartok’s marriage of the folk and the classical. Mr. Tetzlaff was accurate and exacting, never less than assured. He milked certain lyrical phrases more than I would have liked, but that is a matter of taste. He has an obvious enthusiasm for the work, and this served him, and it, well.

The second movement – Andante tranquillo – begins with a kind of song, a violinistic song, and here Mr. Tetzlaff was blessedly unfussy. He then meandered intelligently among Bartok’s notes. He displayed some of the best legato playing you’ll ever hear on a violin. His rapid repeated notes were utterly clear. And his soft playing was not hushed – wrongly hushed – merely lower in volume, if you can imagine: He kept the violin’s, and the line’s, body.

He retained the listener’s interest all through the closing movement – Allegro molto – not neglecting the music’s pulse, its energy. And he was self-effacing in this work, allowing Bartok to have the spotlight. Mr. Tetzlaff was strictly an agent for the composer.

The conductor, David Robertson, apparently shares Mr. Tetzlaff’s enthusiasm for the concerto, and he had the New York Philharmonic playing keenly. Textures were right, reflecting the textures of the work itself. Overall, there was nothing to detract from what Mr. Tetzlaff was achieving.

In the past, I have wondered why the world values this violinist so highly; he did not seem to earn it. But Friday’s performance proved that Mr. Tetzlaff’s reputation is just. At least, it was vindicated on this occasion.

Shall we break for something silly? Okay. In Bartok’s first movement, one can hear something like “Give My Regards to Broadway.” And at a certain point in “Rodelinda” – the Handel opera now playing at the Metropolitan Opera – one can hear something akin to “We need a little Christmas, right this very minute.”

All right, back to sobriety.

Sobriety in the form of Steve Reich, and his orchestral version of his Triple Quartet, a work he wrote for the Kronos Quartet in 1999. This is a version for string orchestra, actually, and the players are divided among three groups of 12.The work is in three movements, amazingly labeled “First Movement,” “Second Movement,” and “Third Movement.”

Mr. Reich is a king of minimalism, and he commands our attention. But I would not judge the Triple Quartet among his stronger works. There is a difference between repetitiveness and monotonousness. Or maybe it’s better to say that there is a difference between repetitiveness and repetitiousness. In this work, I believe, Mr. Reich crosses to the unhappy side of the line. To me, the Triple Quartet is not so much lulling or entrancing or mind-bending as annoying. But Mr. Reich has his fans – no matter what he writes – and they applauded loudly.

The work was not helped by the Philharmonic’s performance, which could have used more flair in rhythm and phrasing. It could have used more musicality, altogether. This would not have spoiled the essential minimalism. As it was, the players rather bulled and sawed their way through.

When the piece was finished – and in anticipation of the final work on the program, Beethoven’s Symphony No. 8 – the lady behind me said to her companion, “Now we get paid back.” Talk like that will get you shot by the commissars, madam.

Mr. Robertson’s traversal of the Beethoven was admirable in several ways. For one thing, he conducted the symphony as though he liked it, which is helpful. And orchestra members seemed to feel themselves lucky to be playing it – which they were. In the first movement, Mr. Robertson engaged in some interesting elongation of notes – or rather, he wrung from them their full value (or perhaps a little more). Toward the end of the movement, however, the playing gained some flabbiness, lost some tension. And technical bobbles were unfortunate.

The opening staccato, repeated notes in the second movement – Allegro scherzando – were far too heavy. One result was that the melody that goes with these notes seemed less than lilting. And in the rest of the movement, inner workings were not as clock-like or graceful as they might have been. The following movement – Tempo di menuetto – was decent, if nothing special. And the last movement, that beloved, unbuttoned, thrilling Allegro vivace?

It ought to begin on a knife edge, or a baton edge – all quivering joy and expectation. We did not get that. It is true that such a feeling requires technical precision – and we didn’t get that, either. But this final movement was no slopfest, and Beethoven was duly enjoyed.

Mr. Robertson delivered a creditable account of the Eighth. And, to repeat (in a nod to Mr. Reich), there was one great performance that afternoon, of Bartok’s Violin Concerto No. 2 by Christian Tetzlaff, and – we must not omit them – David Robertson and the New York Philharmonic.