Since I saw the pianist Lang Lang’s recital on Sunday afternoon, my inbox has been full of messages from people assuring me that yes, he really is a kind of musical antichrist.

What Lang Lang does, supposedly, subsumes the score to his ego in a way that is profoundly anti-musical.

I’ve uttered my share of this kind of criticism of Lang Lang in the past, and I fully expected to feel the same way this week, during his residency with the National Symphony Orchestra. But on reflection, I’m curious about how emphatic so many of us are about staying on this particular bandwagon. I also note that a lot of major musicians don’t hear Lang Lang this way at all.

If Lang Lang is such a cheapener of music, it’s certainly not showing this week. You may not approve of the way he approaches music, but he’s not playing cheap stuff. And having anticipated this week with mixed emotions, I find myself enjoying it.

There was certainly a lot to like in Wednesday’s duo recital by Lang Lang and Christoph Eschenbach, the NSO’s music director, playing Mozart and Schubert on two pianos. Eschenbach has been a musical godfather to Lang Lang since conducting his (unplanned) debut with the Chicago Symphony at the Ravinia Festival in 1999. Given this, and Lang Lang’s reputation for flamboyance, Eschenbach can seem like a wise guru in comparison: Yoda to his Luke.

Star pianist Lang Lang in 2010. (Sean Gallup/GETTY IMAGES)

But that judgment may have more to do with how they look than how they sound. Eschenbach projects a kind of monkish restraint, but he may actually be the more flamboyant, the more emotional of the two. Lang Lang is certainly given to big gestures, but there’s also a solid through line, where Eschenbach can be episodic.

Lang Lang is also the better technician at the moment, simply because Eschenbach, though he began his career as a concert pianist, now maintains such a busy conducting schedule that it is hard to keep his piano skills in top trim. Any technical stumbles on Wednesday night came from Eschenbach, while Lang Lang, in the disciple role, figuratively took his arm.

The performance was certainly a heartfelt exchange between two musicians, playing on two equal instruments, facing each other. Since both are eminently concerned with communication, the resulting dialogue seemed intensely intimate, although I use the word “seemed” advisedly, because this was very much a performance. It was less like listening to a private conversation than like watching two veteran actors enact a two-man play.

The first half was Mozart: the D major sonata for two pianos, K. 448, and the F major sonata for four hands, K. 497. One is written for two instruments; the other can be played on a single keyboard, so Eschenbach took the higher part, Lang Lang the lower. Like Lang Lang’s Mozart on Sunday, this playing was sometimes mannered, sometimes more romantic than Mozart is “supposed” to be. It also had a spark of delight I didn’t always get on Sunday — the third movement of the D major was beautifully fun — and offered the satisfaction of technical accomplishment when two complex high-wire acts suddenly interlock seamlessly to present a new whole.

The last half of the program was all Schubert, including a duo in A minor called “The Storms of Life,” a late substitution to the program. The evening’s emotional heart, though, was a moving performance of Schubert’s Fantasy in F minor. Lang Lang took the upper voice here, and he emoted though the first line in a way that I, in less of a self-questioning mood, would once have raced to condemn. If his physical enactment of the music was distracting, however, it not only sounded pretty beautiful but set the stage for each subsequent appearance of the theme — which returned, like a balm, after the music had tangled itself into such a storm it briefly fell silent.