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.
[1] These études are less technical than the composer's Op.
10 and 25 and retain Chopin's original formula for harmonic and structural balance.
They are often erroneously described as posthumous, due to their lack of an opus number.
This article about a classical composition is a stub.