There are several very important things I must tell you about yesterday’s rehearsal of the chamber symphony. / First the good points: the thing as a whole seems to have been worked out pretty well. Except for some casual and some wrong rhythms and some passages that don’t come out at all, almost everything else would make an excellent impression if it were not that/ (and now come the bad points, which I must state most emphatically and which I wish you to pay the utmost attention to) your tempi were much too fast throughout./ You seem to labour under the delusion that temperament means speed!! But temperament in itself doesn’t mean anything and so far as I’m concerned, if it means ‘fiery temperament’ or the like, it strikes me as worthless, because the most it can do is to impress the womenfolk. Cast off this error and make music with a muted, with a restrained temperament!! / Now for the details: in general, then, this rushing of tempi means losing all the clarity gained by careful study of the score. All the lines become blurred and one can’t understand a thing! / For instance, the first part of the Scherzo is too fast by more than half. The same for the Trio: / That simply won’t do. It must go much slower. / But the main thing is the Adagio: you take it almost allegro!!! Of course it mustn’t be treacly slow, but must have an inward emotion, only adagio, (about 50)!!! Then the B major part of the Adagio much too fast!! This begins quietly and contemplatively, and its intensification must not be passionate, but ‘inwardness intensified’. It’s a remarkable thing: passion’s something everyone can do! But inwardness, the chaste, higher form of emotion, seems to be out of most people’s reach. On the whole it’s understandable: for the underlying emotion must be felt and not merely demonstrated! This too is why all actors have passion and only a very few have inwardness. / I can’t regard it with tolerance! / To go on: the whole recapitulation section is rushed. It’s all fluffed, no note is left clear. Do use only as much expression as in in the piece, and don’t always try to give more! / I beg you to observe these criticisms exactly, if you want to remain on good terms with me!!!(…) I hope you won’t be foolish enough to be cross with me for these strong words. But I have come to realise that bad performances do me so much harm that I can’t go on allowing them. I always used to console myself with thoughts of the future. But recently I have been feeling more and more that every inadequate performance of a work of art is a grave crime, simply immoral.