Today was one of those magic days when an experiment comes out better than any imaginable hypothesis.

Two young people have been learning together four-hand Stravinsky pieces which I do not know. It's fair to point out how much I enjoy teaching music I don't know. Sounds like an oxymoron. But in listening as the students learn I learn to hear as they hear. The questions that arise are deeply artistic and are clearly audible to me in the playing.

Today I asked them if they could imagine why I do not insist that they practice their separate parts at home. "If we did," said one, "we would form an idea of how our part goes without the other part. Then, when we played together, we would not listen to the other part." (The emphasis is mine.)

She articulated exactly what I try to tell people learning chamber music: don't practice your part because you will form an entirely false idea of the music and you will not enjoy the total sound made when all the players are together.

Many trained musicians are unaware of their sensitivity to tone at the vibration level until they experience something wrong. Yesterday a fine pianist expressed her dismay that the horn entrances in Brahms symphonies sound of tune. I should mention that this pianist is also an experienced a capella singer with an excellent sense of centering vocal pitch.

Every combination of unlike sounds involves some compromise of temperament: a vibration here or there makes a huge difference in orchestral music, as it should also in chamber music. Why aren't we more aware of this source of magic and potential trouble?

I believe that the image of discrete pitch embodied in the piano keyboard has locked us into an expectation belied by experience, leaving us mightily confused rather than intrigued. The horns are not out of tune: the temperament of horn intervals is not the same as that of strings. It's the same dilemma as in the Mozart piano concerto in which the piano sounded out of tune (a post in July, 2009 describes that event).

The happiest listener is one who not only tolerates the differences but relishes the tension between them.

Two things are of infinite interest to musicians: vibrations and rhythm. There is no end to fascination with either of these natural elements.

Vibrations we know cannot be repeated: like snowflakes they are individually constituted, new every time.

For rhythm imagine drawing a penciled line on a piece of wood and taking it to be cut. Does the cutter aim inside the line, right at its center, or outside?

How thick is the saw blade? How wide is the pencil mark? How much do you care?

Rhythm is an infinite number of cuts with an infinite choice of pencil widths and saw blades, each one of which you care deeply about. But there is only that one piece of wood.

Taking the notion of imitation even further: A concert of new compositions prompts me to notice that dots on paper are not even close imitations of sound, yet it is clear that some composers treat them as though they are. When there is no discernible relationship between the symbols and the sound I think it is fair to make the question explicit.

Even in cases where the performance is not totally successful a listener can hear moments when the sound-sense of the work penetrates to the player's ear. The result is a moment, however fleeting, of real music.

Probably the most difficult aspect of playing new music is to detect its wit. We risk taking the whole business far too seriously.

It is fascinating to observe how an imitation can so affect our notion of the real thing that the real thing vanishes even as we behold it. This morning I read in the New York Times a review of a ballet performance featuring a live pianist. The reviewer said the piano playing was "too blurred by half."

I wasn't there. I didn't hear it. But it makes me curious to go just to hear what I would hear. I suspect that the reviewer expects the piano to sound like the imitation piano sounds to which we are increasingly exposed in drugstores, on telephone "hold," even in Broadway shows.

An electronically imitated piano does not have strings. It cannot reproduce or even evoke the complexities of sympathetic vibration that are the piano sound. We are producing a whole new generation of pianists who strive to emulate the homogenized and pasteurized sound of the electronically imitated piano. Piano teachers seem dedicated to this sterilized notion of sound, perhaps to enable their students to practice on electronic keyboards without too much trauma. Are these proper manifestations of the power of the marketplace?

I suspect this reviewer had such a cleaned up model in mind when he pronounced the playing blurry.

In a brief chat yesterday a former student clarified my notions about what a sonata is (it sounded like a reprise of the review I gave Victor Rosenbaum on his reading of Beethoven Op. 2 #3). To wit, more or less: A sonata is not a matter of a selection of notes which constitute a theme or two, but rather an acoustical proposition that reveals the nature of the instrument(s) for which it is written.

It's not a bad definition, since it can be extended to cover the various instrumental combinations for which sonatas have been written, including piano trios and string quartets, among others.

It would be a fascinating study to detect the actual acoustical difference between a Mozart piano sonata and a Mozart string quartet in D major, for example. This is something I have long dreamed of doing.

Why not start today?

We think of tempo as affecting playing, not listening. It is equally important in both musical activities. Most of us think of listening as passive. It is anything but.

32,000 vibrating sensor-tipped hair cells in the inner ear represent an enormous amount of activity.

It would be interesting to play with your internal metronome in relation to your listening. Say you are about to hear a Minuet: Start by imagining how a minuet might go. Get in gear, so to speak. You will have a definite reaction immediately as the music starts--you will be engaged. Or imagine that you are hearing a chamber music performance in a small space and that you decide to pay attention to every entrance of the clarinet. You will probably notice events happening much more rapidly than can be accounted for by any normal sense of the beat -- so much goes into the production of a tone!

These decisions you can make about your active listening can be the basis for real listener empowerment. Every performer needs and appreciates active listeners!