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.

Ch. 6 : Chopin: Virtuosity Transformed - The Romantic Generation (1995)