Classical piano sheet music by Chopin to download: Waltz Op. posth. in the key of This piece has difficulty level 7 in the category Piece Waltz Op. posth. in E Minor, a composition by the early romantic composer Frédéric Chopin who was born in 1810 and died in 1849. The piano score of this piece was first published in 1829 and is part of Chopin's Waltzes.