Anton Bruckner was kind of nuts. Don’t follow the common mistake of thinking of him as an idiot savant, begged the program notes to the National Symphony Orchestra’s concert Thursday night — and then failed to give us any reason why we shouldn’t.

He was a bit of a hick, socially awkward, reclusive, alternately stubborn and unsure. He also loved music with a dogged devotion that moved his uncompromising soul to tremendous flights of poetry that are all the more poignant because they were wrested from such a craggy surface. His Seventh Symphony is one of his most lyrical works — the piece in which he had the easiest time finding a way to combine the monumental and the beautiful.

And here the reviewer comes to a roadblock. Some readers say they don’t want to hear about the music; they want to know how the performance sounded. For others, exposure to the music is wonderful whether the performance sounded good or not. What exactly does it serve to know which entrances were botched, which soloists stood out, when you are hearing a piece as powerful as this?

If you were one of the people who left in a hurry at the end of Thursday’s long reading of it, though, it might help to know that the NSO’s performance sounded sluggish to my ear, even turgid in places, and that other performances might suit you better.

I don’t mean to slam the orchestra unequivocally; there was a lot to like. Christoph Eschenbach approached the piece with reverence and love, and without a score, conducting from memory the big, arcing movements that are so often described, like all Bruckner symphonies, as “cathedrals of sound.” That’s an epithet I heartily wish we could abolish, only because it has become an easy label that spares people the need to engage on any deeper level.

“Proto-Minimalist” is another frequent Bruckner epithet, but one I have an easier time with, because it gets across something about the composer’s unconventional approach, stacking one section of music atop another, rather than developing his themes in the traditional manner of classical music.

Eschenbach loves Bruckner, and listening to him, I thought he can be a little like Bruckner, at least in his free-thinking quirkiness. He approached each musical block on its own terms, giving it plenty of room to breathe, so that there was something ponderous and a little wobbly about how they all fit together. But he kept something in reserve and pulled a surprise out of his hat with the fourth movement, often called the symphony’s most problematic. Here it was the standout, opening with the spark and verve that was previously missing and amassing the full power that had been slightly in abeyance earlier.

The conductor, in short, was going somewhere all along. I may not have agreed with the journey or found it set off all of the work to best advantage, but I appreciated the sense of it coming together.

The program began with another treat: Wagner’s “Wesendonck-Lieder,” five songs to texts by his lover Mathilde Wesendonck, in a ravishing orchestration by Hans Werner Henze. Wagner did orchestrate a few of these songs: one, “Traume,” straightforwardly, and both “Im Treibhaus” and “Träume” additionally as part of the score of the opera “Tristan und Isolde.”

Since this opera is one of the watersheds of 19th-century music — some would say of Western music — reorchestrating these songs represents a tall order, but Henze rose to the challenge with something delicate (it’s written for chamber orchestra) and shimmering and his own. This 1976 orchestration wraps Wagner in a soft veil of love and nostalgia that feels at once not quite Wagnerian and very much in the spirit of the works.

The instrumental opening of the first song, “Der Engel,” was gorgeous. Alas, the set as a whole fell victim to the uneven intonation, rhythm, audibility and artistry of the contralto Nathalie Stutzmann. And a sluggishness set in partway through that the orchestra didn’t shake off until well into the Bruckner.

The program repeats Friday and Saturday nights at 8.