Jonathan Biss is a classical pianist who's climbed one of the biggest mountains, playing all 32 of Beethoven's sonatas for solo piano. It almost wrecked him. The music, especially the later works, are psychologically dense, to say the least. Ludwig van Beethoven was not the first composer to live through anguish and despair in his physical and mental health, but he was the first to reflect it so profoundly and directly in his music.

In his new audio memoir, Unquiet: My Life With Beethoven, Jonathan Biss talks about how the journey through the sonatas challenged his own mental health and struggle with anxiety. He also has a new concert recorded at GBH that you can stream online starting this weekend at Biss joined Arun Rath on GBH’s All Things Considered to discuss Beethoven’s works and the toll that it took on him.

Listen to the attached audio to hear snippets of Biss’s performances in the interview. What follows is a lightly edited trancript.

Arun Rath: So as we're going to talk about Beethoven and mental health and your journey with Beethoven, I think for people who may not be familiar, it's helpful to to set the stage — what it means for a pianist to take on all 32 of Beethoven's sonatas. Because for people who know Beethoven, he started his life and ended his life with a piano, right? And all of the drama and intense emotion, from lost loves through losing his hearing, it's all in that music, right?

Jonathan Biss: Yeah, I'm hardly the first pianist to call the 32 Beethoven sonatas the Mount Everest of the repertoire, and I think it's an apt description for many reasons. I mean, obviously just first of all, the sheer volume of music, I mean, 32 pieces, almost none of which are small, the incredible variety of expression, of structure, of character in the music.

But I think maybe more than either of those things is the incredible intensity of Beethoven's personality. There's really nothing else in music that's like it, the extent to which he forces you to invest every ounce of yourself, your intellectual self, your psychic self. So, I mean, playing all of these feels like a profound undertaking to play — all 32 of them is wonderful, but utterly overwhelming.

Rath: You have this line — we'll talk about how it came to a point of even emotional breakdown for you. But even before that, you have this line that's actually in your audio book, it's very dramatic. I bet if I started, you maybe even could finish it. That's on April 24th, 2007...

Biss: Beethoven's Sonata Opus 109 made me lose my mind. I mean, as funny of a thing as it is that I'm about to say, given that the line is a dramatic line, I feel like choosing that sonata in that recording session that day was in a sense arbitrary. Because there were so many moments, and there have been so many moments in my life with Beethoven, where I felt like the desire to say something about his music that was true and that conveyed the essence of it — in all of its, as I said, intensity and all of its profundity — that my desire to do that, and the difficulty of doing it, really just started to seem more than I could bear.

Rath: Well, it's interesting to use this phrase "lose my mind." And there are other places where I notice you talk about losing yourself in Beethoven and in this music. How did that happen? I mean, you know, we can listen to this music and hear the intensity of it. But when you're playing it, what's going on?

Biss: I think that that thing — of feeling like I was losing myself — is very much connected to him. Because again, I think his personality is so enormous and also, I would say, so belligerent. He again, in a way that I would not say was true of any other composer, certainly not to the same degree, he takes up a lot of space. You know, this is a person who had a very unhappy personal life. A composer who recognized that he was losing his hearing from around the age of 30, already, and who wrote to his brothers that the only thing keeping him alive was this need to communicate through the medium of music. And you hear that, you feel that, when you listen to — or play — his music. You feel the sort of life-or-death quality in the way the music comes out of him.

And when faced with that, you feel like your whole being becomes kind of consumed with him and his needs, and attempting to bring that essence to life. And if you aren't careful, sometimes it means there's no corner of the room left for yourself. And I feel like I wasn't attuned enough to myself to sort of guard against the dangers inherent in taking on a personality of that enormity and that intensity.

Rath: Let's get to an example of that intensity. And, set up brilliantly, you're recording a pretty famous piece: the Waldstein Sonata, that's Opus 53. And, I gotta say, Jonathan, your recording of this, I think, is my favorite version of it. It's a piece that we'll hear as it starts off. Everybody who plays it sounds, you know, intriguing and hear that emotionality. Let's hear a little bit of your recording and then we'll talk about it.

Musical interlude, listening to a snippet from Biss’s performance of the Waldstein Sonata.

Tell me if you think I'm wrong headed in hearing this, but when I hear this, you playing it, there's something scarier here than I hear in most versions. It feels like other versions feel a little bit safe compared to this.

Biss: Oh wow, thank you. I'm happy to hear that — I know that 'happy' sounds like a funny word to use in this context. But I do think one of the signature qualities of the Waldstein Sonata — and maybe sometimes underplayed — is there's a sense of wonder in it that comes through sort of from the first notes. And I think that that wonder is maybe threatening at times to go in a darker direction.

I mean, certainly there's a way in which — you hear this from the first phrase — that the music is often really quite evenly poised between the major and the minor. It happens again in the last movement, there is this sense of being in some kind of no man's land between the two modes.

Rath: It takes me right to these two phrases that also stick out from your audiobook, where you're talking about your own troubles with anxiety, and you say, "Anxiety is complicated, Beethoven is complicated."

Biss: Yeah, absolutely. And I mean, the maybe most important thing that I've had to do to come to terms with my anxiety was to stop wishing or hoping that it would simply go away. Living with it, when you're particularly prone to it, as I would say, I am, is it about accepting it as an integral part of yourself and learning how to recognize the point where you cross that line from it being a healthy, motivating life force and then turning into a monster that might eat you. It's really hard to do that when you're working on Beethoven, because Beethoven asks you to throw caution to the wind.

Rath: It sounds like you've come to a point now where you're able to function and you're still able to play Beethoven.

Biss: No, I feel much more able to play him now that I'm kind of in balance as a person. Performers have been trained — to our detriment — to believe that if you have any difficulty handling your emotions, you're ill suited to your job. And so I think, for so many years, I felt like to say, "I have anxiety," was really just another set of words to say, "I'm a failure in my chosen profession." And I had to get past that, which was hard! And it took a long, long time, and it took me hitting what I would personally call my bottom to be able to sort of say, "I have a problem." So that was the first, and I think I would still say, the most difficult step.

Rath: Jonathan has been a real pleasure speaking with you. Thank you so much.

Biss: Oh, it's my pleasure. Thank you for having me.

Musical outro.