The importance of these proportions [six group of instruments] for the clarity and plasticity of the musical line was very clearly shown at a rehearsal of 'Apollo' conducted by Klemperer in Berlin. From the very first pages I was struck by both the confusion of sound and the excessive resonance. Far from standing out in the ensemble, the various parts merged in it to such an extent that everything seemed drowned in an indistinct buzzing. And this happened notwithstanding the fact that the conductor knew the score perfectly, and scrupulously observed my movements and nuances. It was simply a matter of the proportions of which I have just been speaking, and which had not been foreseen. I drew Klemperer’s attention to it immediately, and the necessary adjustments were made. His ensemble had consisted of sixteen first and fourteen second violins, ten violas, four first, and four second violoncellos, and six double basses. The new arrangement was eight first and eight second violins, six violas, four first and four second violoncellos, and four double basses. The alteration immediately produced the desired effect. Everything became sharp and clear. / How often we composers are at the mercy of things of that sort, which seem so insignificant at first sight! How often it is just they that determine the impression made on the listener and decide the very success of the piece! Naturally the public does not understand, and judges the piece by the way in which it is presented. Composers may well envy the lot of painters, sculptors, and writers, who communicate directly with their public without having recourse to intermediaries. << less