By the late eighteenth century, there is a sad and permanent decline in the quality of music written for young performers or beginners: one has only … - Charles Rosen

This is the true paradox of Chopin: he is most original in his use of the most fundamental and traditional technique. That is what made him at the same time the most conservative and the most radical composer of his generation.

The etude is a Romantic idea. It appeared in the early nineteenth century as a new genre: a short piece in which the musical interest is derived almost entirely from a single technical problem. A mechanical difficulty directly produces the music, its charm, and its pathos. Beauty and technique are united, but the creative stimulus is the hand, with its arrangement of muscles and tendons, its idiosyncratic shape.

The absolutely inaudible is rejected from music during the period of Viennese Classicism in which every musical line is potentially or imaginatively audible, but it makes a dramatic reappearance in the music of Schumann. The most striking of many examples is one of the episodes in the Humoresk, the last of the great piano works of Schumann's early years. ... There are three staves: the uppermost for the right hand; the lowest for the left; the middle, which contains the melody, is not to be played. Note that the melody is no more to be imagined as a specific sound than it is to be played: nothing tells us that the melody is to be heard as vocal or instrumental. This melody, however, is embodied in the upper and lower parts as a kind of after-resonance-out of phase, delicate, and shadowy.