The trouble with reacting to a live performance is that it is hard to distinguish reactions to the music from reactions to the performance. A great admirer of Morton Feldman's music took issue with yesterday's post, pointing out that silence is absolutely necessary in order to hear it.

Isn't silence necessary in order to hear all piano playing? I think it is the job of the pianist to achieve that silence within the playing itself, not through either public announcement or theatrical gestures.

Holding the attention of the audience is the art of performing the music of every era. What have we lost? How did we lose it?

I suspect that the answers lie in the economics of the concert world: it is not cost-effective to perform in small halls, therefore the finer nuances of sound are not cultivated by aspiring professional pianists. Also, whatever nuances remain are often lost in the recording and reproducing processes. The loss compounds with every remove from the performance itself: microphones, speakers, ear phones, ear buds, etc. all restrict the life of the vibration. The subtlety of our auditory culture is increasing diminished.

An utterly sanctimonious air reigned during the 95 minute performance last night of a work by Morton Feldman for piano solo. Starting with the pianist's grimaces and other expressive manifestations the audience of about 60 people in a small/midsize theatre felt obligated by a pre-concert admonishment from the management not to disturb anyone with any sound whatsoever. I wasn't the only one stifling yawns, shifts of position, coughs and other natural urges.

All of this was completely beside the point, it seems to me. The pianist is a truly fine pianist who handled a less-than-perfect instrument as well as anyone could have. So what was wrong?

The monotonous aspect of the evening was too much for this listener. Could there really be no humor in this music? Not so from what I heard. But if you start out demanding no reaction from the audience it is hard to imagine anyone daring to laugh. Feldman gives lots of color and many darting shifts of mood to deal with. Where was the response of either the player or the public? Streng verboten, apparently. I wonder, in the name of what?

Yesterday I had two excellent reasons for using theoretical categories warily: one was the first movement of Beethoven's "Moonlight" Sonata, the other the Allegro innocente movement of a well-known Haydn Sonata in G.

Looking first at the Beethoven with a theoretical eye, one sees a triad repeated four times in the right hand over a whole note in the bass. Listening to the piano, however, one hears an unfolding of overtones releasing a wealth of sonority far richer than a triad. This is especially true if the twelve units of the four triplets are grouped in fours rather than threes. Try it: you will be amazed at how much more interesting (and difficult!) the piece becomes.

As for the Haydn: I asked the young student to identify the most frequently sounding tone in the first four bars. The answer, not G but B. Played with B in the foreground transforms everything in the movement. All of the wit of this clearly humorous movement is revealed as turning on that unlikely tone. Try that, also.

Brilliant composers for the piano rarely used static harmonies because the instrument comes alive in its overtones. Trust it.

Music is many different things. The piano is many different instruments. Each depends on context, usage. Each might be said to resemble a mirror, reflecting sometimes distorting, sometimes revealing.

Keeping an open mind about these things has enabled me to take seriously the work of even an extremely developmentally challenged young man, one of my young students. He has access to tonal logic; at times that seems dangerous to me as he risks being locked into a tonal world of only one possibility. Listening to him open his ear to other possibilities has been a revelation for everyone privileged to observe his progress.

A development in modern composition pairs the piano with percussion: perhaps it was Bartok who started the imagination moving in that direction with his Music for Two Pianos and Percussion. How different from the early days of the piano when the fascination was with the piano as a stringed instrument, capable of many acoustical effects in common with stringed instruments, therefore compatible with them in duos, trios, quartets and so on.

As concert halls grew the sound of the piano became more and more steely--more percussive. The sustaining, shimmering, accepting acoustics of the instrument were no longer audible, except close up. And how many public events took place in small rooms? Everyone knows that is not cost-effective.

So the percussionists moved to front and center and it is their sounds that pianists match, even when playing solo.

Please don't misunderstand me. One of my dreams since childhood is to live in a home with one entire room filled with gongs, drums, bells, triangles -- the whole nine yards. I love percussion and greatly admire the increasingly subtle musicianship of percussionists.

But even more than percussion itself I love the piano's versatility and bemoan its loss. Why can't one learn to play this amazing instrument both ways?

Within the past two days there have been references in the New York Times to the fear-filled experience of youthful music study. One appeared in the obituary of a prominent cellist who, realizing that his young students were in tears but not learning anything, decided to "lighten up." The other was in a reader-submitted tribute to a recently deceased high school orchestra teacher.

What was striking about the first was that the teacher recognized in the distress of his young students the need to change his tone. In the other piece I was struck by the fact that the writer had not touched her viola in so long that her teenage children didn't even know she had one. Her connection to the teacher was real, but her connection to music had remained frozen.

She describes a reunion concert in which all the warm human interaction accessible through music is evoked, albeit through the misty veil of sentimentality. People get nostalgic even for the experience of being mocked and belittled, which she recalls vividly as part of the orchestra experience.

Had it been otherwise the viola would not have been untouched for so many years.

It occurs to me that fear-filled is dreadful.

Playing for an audience intensifies everyone's listening, especially the performer's. It can be unnerving to realize, even while playing, that one is hearing things with new intensity. That accounts for much of what we call stage fright.

How refreshing, in contrast, to hear young people perform whose training is based on the immediacy of their ear. The attentiveness of the audience seems to reinforce confidence in their hearing so that nothing rattles them.

My class of young students had a playing party this afternoon in which that was once again demonstrated.

Bravo to their parents for taking the long view of what music means.