Frédéric Chopin wrote his Trois nouvelles études ("three new studies") for piano in 1839, as a contribution to "Méthode des méthodes de piano", a piano instruction book by Ignaz Moscheles and François-Joseph Fétis. They are often erroneously described as posthumous. In general, these études display little of the technical brilliance of most of the composer's Op. 10 and 25, though they do retain Chopin's original formula for harmonic and structural balance. The third and last étude, in D-flat major, is probably the most technically challenging in this collection, while still being far more manageable than most of the composer's Op. 10 and 25 studies. It develops independence of voices and articulation in the right hand, with the upper melodic line quite legato over a staccato alto accompaniment. Some of the reaches required between the alto and soprano lines might be difficult for pianists with smaller hands.