What can I tell you about interpretation? I really ought to talk to you about it rather than write, as I should need thirty pages. In a very imperfect manner I could recapitulate the method which in stages guides us, as I believe, to the truth.
First, one should try to discover the complete emotional content of a work by playing it a great deal in various different ways before ever starting to play it ‘technically’. When saying ‘playing it a great deal’ I think above all of playing ‘mentally,’ as the work would be played by the most perfect of interpreters. Having lodged in one’s mind an impression of perfect beauty given by this imaginary interpretation — an impression constantly renewed and revivified by repetition of the performance in the silence of the night — we can go on to actual technical work by dissecting each difficulty into a thousand pieces in order to eliminate every physical and technical obstacle; and this process of dissection must not be of the whole work played right through but of every detail taken separately. The work should be done with a clear head and one should beware of injecting any sentiment.
Finally comes the last phase, when the piece, mastered technically throughout, must be built up architecturally into its overall lines and played right through so that it may be viewed from a distance. And the cold, clear-headed and insensitive being who presided over the whole of the preceding work on the material of which the music is made, takes part in this eventual performance as well as the artist full of emotion, of spirit, of life and warmth who has recreated it in his mind and has now discovered a new and greater power of expression.
Forgive me for expressing myself so badly about something so solemn. I hope it will not seem incomprehensible to you.