From Mozart’s letters, one learns something about his own manner of playing the piano:

“Herr Stein sees and hears that I am more of a player than Beecke—that without making grimaces of any kind I play so expressively that, according to his own confession, no one shows off his pianoforte as well as I. That I always remain strictly in time surprises everyone; they cannot understand that the left hand should not in the least be concerned in a tempo rubato. When they play, the left hand always follows” (1777).

About Nannette Stein’s playing: “She sits opposite the treble instead of in the middle of the instrument, so that there may be greater opportunities for swaying about and making grimaces. Then she rolls up her eyes and smirks. If a passage occurs twice, it is played slower the second time; if three times, still slower. When a passage comes, up goes the arm, and, if there is to be an emphasis it must come from the arm, heavily and clumsily, not from the fingers. But the best of all is that when there comes a passage (which ought to flow like oil) in which there necessarily occurs a change of fingers, there is no need of taking care: when the time comes you stop, lift the hand and nonchalantly begin again. This helps one the better to catch a false note, and the effect is frequently curious” (1777). Nannette was then eight years old.

At Aurnhammer’s: “The young woman is a fright, but she plays ravishingly, though she lacks the true singing style in her cantabile; she is too jerky” (1781).

“Whenever I played for him [Richter, a pianist], he looked immovably at my fingers, and one day he said, ‘My God! how I am obliged to torment myself and sweat, and yet without obtaining applause; and for you, my friend, it is mere play!’ ‘Yes,’ said I, ‘I had to labor once in order not to show labor now’” (1784).

“It is much easier to play rapidly than slowly; you can drop a few notes in passages without anyone noticing it. But is it beautiful? At such speed you can use the hands indiscriminately; but is that beautiful?” (1778.)

“Give me the best clavier in Europe and at the same time hearers who understand nothing or want to understand nothing, and who do not feel what I play with me, and all my joy is gone” (1778).

“The andante is going to give us the most trouble, for it is full of expression and must be played with taste.... If I were her [Rose Cannabich’s] regular teacher, I would lock up all her music, cover the keyboard with a handkerchief, and make her practice on nothing but passages, trills, mordents, etc., until the difficulty with the left hand was remedied.”

Saint-SaËns, lover of irony and paradox, wrote a preface to his edition of Mozart’s pianoforte sonatas, published at Paris in 1915, in which, after a discussion of the ornaments, he has this to say:

“One is accustomed in modern editions to be prodigal with liaisons, to indicate constantly legato, molto legato, sempre legato. There is nothing of this in the manuscripts and the old editions. Everything leads us to believe that this music should be performed lightly, that the figures should produce an effect analogous to that obtained on the violin by giving a stroke to each note without leaving the string. When Mozart wished the legato, he indicated it. In the middle of the last century, pianists were still found whose playing was singularly leaping (as one may say). The old non-legato, being exaggerated, became a staccato. This exaggeration brought a reaction in the contrary sense, and this was pushed too far....

“This music of Mozart during his early years is destitute of nuances; occasionally a piano or a forte; nothing more. The reason for this abstinence is because these pieces were written for the clavecin, and its sonority could not be modified by a pressure of the finger. Clavecins with two keyboards could alternate with forte and piano, but nuances, properly speaking, were unknown to them.

“In the 18th century, one lived more quietly than today, nor were there in music our modern habits of speed, which is often inflicted on ancient compositions to their great injury. It is necessary to shun in the case of Mozart this tendency to hurry the movements, as too often happens. His presto corresponds to our allegro; his allegro to our allegro moderato. His adagios are extremely slow, as is shown by the multiplicity of notes sometimes contained in a single beat. The andante is not very slow.

“It was the rule, in his time, not to put the thumb on a black key except from absolute necessity. This method of fingering gives to the hand great restfulness, precious for the performance of old music that demands perfect equality of the fingers.

“The first pianofortes were far from having the powerful sonority of the great modern instruments. Therefore, it is not always necessary to take Mozart’s forte literally; it is often the equivalent of our mezzo forte.”