“In Lars’s words, which I think we all share,” Christian said, “the incredible difference between Schubert and Brahms is that Schubert shows you the absurdity, the horror and the beauty of everything, and Brahms actually takes you by your hand, and tries to give solace.” With Brahms, he added, “you have somebody at your side who is very much like you, and suffering like you. Whereas you are next to Schubert, and say, ‘Who is this giant?’”

For the Tetzlaffs, Schubert’s E flat trio represents Vogt’s emotional landscape, as well as the strength he showed in the face of his illness. Finished in November 1827, the piece dwells on Beethoven’s death earlier that year: It is in the same key as Beethoven’s “Eroica” Symphony, and it likewise centers on a funeral march, in C minor, whose shadow is cast off only in a finale that takes consolation, of a sort, in compositional virtuosity, delighting as it layers themes on top of one another.

“This is like a psychodrama with Lars dealing with the situation,” Christian said. “He would still have the loudest laughter and the wildest demeanor, engaging with us. But this is also what Schubert is doing in that slow movement: dealing with pain in a way that is not hiding, and not getting smaller, but getting bigger.”

The funeral march, with moments of dignified hope that are interrupted by outbursts of extreme turmoil, is clearly a reckoning with the abyss, so much so that Schubert demands the impossible from the people playing it, much as grief asks of its sufferers. There is one point where the string lines are marked triple forte, yet crescendo from there, accents spiking the way. It’s unplayable writing, for unspeakable emotions.

“He says, ‘Deal with it; say something,’” Christian explained of Schubert in those moments. “But how?”