You can tell Emanuel Ax and Yefim Bronfman have been friends for more than three decades. They finish each other's sentences. They have nicknames for each other, "Manny" and "Fima." And for the last five years, they've even lived in the same New York City apartment building. In the midst of rehearsing for their recent tour, the two chatted (and joked) with Jason Victor Serinus about the challenges and joys of performing two-piano repertoire.

Jason Victor Serinus: How do you give each other cues back and forth? I assume you can see each other's heads, but not the hands.

Emanuel Ax: That's correct.

JVS: Does this make it harder to be spontaneous in the moment?

EA: It certainly calls for lots of rehearsal. After a while, you start feeling each other's impulses. The more you rehearse, the more spontaneous you can be.

JVS: How long has it taken to get to that point?

Yefim Bronfman: After four tours in 10 years, we know each other quite well. Actually, when we rehearse, our pianos are side-by-side most of the time, so we can see each other's hands.

JVS: Great. But you obviously can't do that in performance.

YB: After you rehearse six or seven times, you begin to know what the other person's hands do. When you finally sit in the proper position, you sort of see their hands moving in your head. You can almost anticipate what the other person will do, or not ...

EA: [chuckling] Or not.

YB: Actually, I find playing two pianos to be the most difficult form of playing chamber music because ...

EA: ... the sounds are so direct.

YB: It only takes one inch [to] push the key down.

EA: On a string instrument, you have more physical space to sound your note. For two pianos you really have to play together to sound together.

YB: I find it much easier to play with a violinist than with another pianist. You have less distance. When you play with a string player, you can use the whole bow: which is a couple of feet long: to make the sound. When you work with a pianist, it's only an inch. That split second is more subtle and more difficult to match.

JVS: Isn't there a lack of contrast between the sounds of two pianos that affects your ability to create poetry?

YB: Being a pianist is more like being a conductor. The breathing before playing the note and making nuance on the note requires you to physically prepare beforehand. When you play a string instrument, you can actually make a crescendo and a diminuendo without changing the bow. With pianos, it's more complex to be synchronized musically and technically.

JVS: What part of your program has proven easiest to fall into place?

YB: I think the intermission is the easiest. [laughing]

EA: The Brahms and Rachmaninoff we've both recorded and played before on previous tours. The Mozart and Bolcom are new for us.

YB: I'm learning the Mozart as we speak. I'm relying on Manny to teach it to me.

EA: And I'm relying on Fima to get me out of my bad habits. So we'll be fine.

JVS: The Mozart is a joy from start to finish.

EA: It's a very nice piece. I wish I'd written it. [laughing]

JVS: Like some partners, do you two end up arguing and fighting to the death over interpretation?

YB: We've never fought.

EA: We don't argue; we just play and work until it sounds good. Fima will make a suggestion, and we'll try it. If it doesn't work, we try something else.

YB: We never argue as long as it's done Manny's way.

Music critic Jason Victor Serinus writes for Opera News, Stereophile, American Record Guide, San Francisco Magazine, and Muso.