Here is how it all started. One of my sons is a piano student at the Florence Conservatory with Maestro Giovanni Carmassi. The scene is the early days. I hear him practice day after day. He starts a new piece and reaches a satisfactory level fairly quickly: he gets the notes right, the rhythm too. I am a music lover, but not a musician, and to me it seems he has achieved the goal. But I am wrong: this is just the beginning.

A few days later I hear him playing the same piece. Now the music has taken on a different character. It sounds more beautiful and expresses aspects I had not perceived before. Time passes, and I hear it again. Once more it has new polish and greater depth. I think: now he has it, this is a fine result! But soon enough comes an even more brilliant interpretation, revealing a secret and amazing quality that was not there before. Thus I find that the piece I thought I knew continues to disclose newer aspects. In short, I am receiving the Maestro's lessons too. Music is like a bottomless well of manifold wonders. You can skim the surface: or you can dive in deep.

After having heard my son's pieces for some time, I finally attended a class recital. To be honest, I have always had reservations about music recitals or plays put on by students. Sometimes the performances are fine, but often they are full of mistakes, hesitations, memory lapses and other disasters. The kids are nervous and clumsy. The parents, noblesse oblige, are forced to heap on the praise.

But this was something quite different. We were listening to performances of great beauty. I wanted to understand better what was happening, so I sat in on a few piano lessons during the summer course that Maestro Carmassi holds every year in Lizzano in Belvedere.

These lessons are spectacular. The students, clever and intuitive, promptly respond to Carmassi's suggestions. Like a Zen master, he leads them to a place where they can find a state of grace, in which the music simply plays itself, without effort or deliberation. But they must beware: they cannot afford to trust that a state of grace will arise.That only happens when you are lucky; normally you have to work hard. The chosen pieces are often not well known. This saves them from slipping into hackneyed musical expression.

The Maestro often uses metaphors. I could give lots of examples, but will quote here a just few. Speaking about the last movement of Chopin's second sonata, he tells a student: "This piece comes right after the famous Funeral March: you must think of it as a gateway to nothingness. After death comes the void; the fast notes are like dry leaves blown away by the wind." To another pupil, who is perfecting the last part of Schumann's Papillons, he remarks: "Here the atmosphere resembles the feeling you get when 'the carnival is over': it is dawn, and everybody has gone ; think of the famous scene in Fellini's I Vitelloni". And again, working with a student on a piece by Scriabin, he says: "Imagine glowing embers – only later will the flame flare up; the tension is as yet latent." And so the lesson goes on, metaphor after metaphor. The pupils listen, and play their pieces again. Notes and rhythm are identical. It is almost exactly as before – yet it is completely different. The piece is transfigured.

Does this mean the students have to keep in mind the metaphor assigned to them, and use it as a reference point while they are playing? Absolutely not! Straight after making his suggestion, the Maestro says: "Now forget it, pretend I said nothing!" The metaphor drops into the unconscious, and there it carries out its remarkable work. The pupil is free to create his own interpretation. Indeed the same suggestions given to different students will bring different interpretations. In those lessons you see not only the art of piano playing, but also the art of teaching.

After some time I proposed to the Maestro a series of interviews aimed at bringing out the salient themes in his teaching. The result is this book. In working with him, I have realized he has more than just the instinct of a good musician and teacher. His work is the distillation of a system expounded over years of effort and reflection. The principles are clear, and sometimes run against the ruling methods, and even against what may at first seem logical. The main ideas are: a musical piece is carefully constructed in one's inner world, never improvised; the pianist puts her whole being into each note; mechanical playing is banned; likewise virtuoso and imitative playing. In a musical piece every muscle, breath, thought, each kind of memory (there are more than one), and above all the soul, together contribute to create the emerging sound.

Partly in jest, partly in earnest (I have never quite understood the respective proportions), the Maestro often says that music is a nasty illness, and that he feels guilty about passing it to his students, because one never recovers from it. I think I know what he means: He takes them by the hand and leads them far away from the trivialities of everyday life to an enchanted world, which it is impossible to leave: so strong is its magic.

The bewitching power of music may be partly lost in an age when works of art can be technically reproduced. But Carmassi prefers the 'here and now' of the concert. Like Walter Benjamin, he is sure that it is the living presence of music – its unrepeatability – that gives meaning and value to a musical piece. Though it may be useful and instructive to listen to a recording, it will be a pale copy It is the difference between a living person and his photograph.

"Don't waste notes!" is another favourite of the Maestro's precepts. He means that every note counts, and must not be glossed over or used as filler. "Each note counts" is a beautiful idea, because it shows that even the tiniest part of a musical piece holds a gem.

Reflecting on this theme, I recall a Middle Eastern tale: Three young brothers decide to go out into the world and bring back an extraordinary object. The first brother, after many travels, brings home a magic mirror with which it is possible to see everywhere. The second brings back a flying carpet that can go anywhere at all. The third brings a fruit, the squeezed juice of which has the extraordinary property of healing any sickness. Once the three brothers are together again, they notice, thanks to the magic mirror, that a princess is dying. With the magic carpet they arrive at her bedside in moments. The magic fruit heals her. It is clear that one of the brothers will have the privilege of marrying her. After all, each one of them made an essential contribution. But who will it be ? The princess chooses the third brother, the one who gave the fruit, because while the mirror and the carpet could be used again and again, the juice of the fruit could be given only once, never more. The young man who offered it knew that in the act of saving the princess he would lose his magic forever. That was proof of true love.

It is the same for the spontaneity and unrepeatability of beauty. In the singularity of this execution, in the atmosphere of this moment, which is about to pass forever and which no one will ever relive: this is where beauty reveals itself. Here the drama and wonder of human life burns bright. In a concert you are watching the life of a musical piece. Therein lies its authenticity, precisely because each performance is unique. If you listen to (or play) music with this attitude, it will seem something altogether different – like the juice of the magic fruit.

We live in strange times. Attendance at classical music concerts is falling (the data are contradictory, however). Some people are predicting the end of the classical concert era. Meanwhile, to give but one example, we find available 87 different versions of Beethoven's symphonies. Much recent scientific research shows that the study of music increases intelligence and brain mass, improves academic performance (including accomplishment in maths and literature), is more effective than computer science in developing abstract reasoning, fosters self-discipline, reduces the likelihood of substance abuse, improves physical coordination, lowers anxiety, enhances qualities very useful for work, such as creativity, flexibility, the ability to communicate and to solve problems.

These are amazing data that ought to encourage everyone. We can only hope someone considers them in planning school curricula. Still, they are just interesting fringe benefits: they cannot be the main motivation for in depth musical study. You do not play the piano to have a more efficient brain or better school results. The motivation, it seems to me, must be music itself – to be studied with humility, attention and resolve.

And above all with honesty: first, honesty with yourself in the work of building a piece of music; and second, with the audience. Let us remember an essential point: Carmassi teaches that in this job you cannot pretend, not even for a minute. You play what you are – this is the most transparent job in the world. The pianist performing a piece before an audience, is vulnerable because he comes out in the open, and because he can blunder at any moment. He is in a situation similar to that of a trapeze artist performing his act: one moment of inattention, and catastrophe happens. It is a dangerous game. This is to live the music.