Etudes, Op. 25
Chopin's second set of Études was published in 1837, and dedicated to Franz Liszt's mistress, Marie d'Agoult, the reasons for which are a matter of speculation. Chopin's Études were the foundation of a new system of technical piano playing that was radical and revolutionary. They are some of the most challenging and evocative pieces of all the works in concert piano repertoire. Because of this, they remain popular and are often performed in both concert and private stages.