Mozart praised the Stein piano for its knee-levers, allowing the composer to operate the dampers without removing his hands from the keyboard; and also for their escapement, which the piano maker had not quite perfected.
In a letter to his father, Leopold, he wrote:
In whatever way I touch the keys, the tone is always even. It never jars, it is never stronger or weaker or entirely absent; in a word, it is always even. It is true that he does not sell a pianoforte of this kind for less than three hundred gulden, but the trouble and the labour which Stein puts into the making of it cannot be paid for. [ 1 ]