Frédéric Chopin: Polonaise Op. posth. in G Minor from Polonaises - piano sheet music to print instantly. This piece is level 5 and was composed during the Early Romantic period. This piece is composed by Frédéric Chopin and was composed in 1817. Title: Polonaise, Op. posth. in G Minor from Polonaises. The difficulty level if graded by ABRSM would be approximately 5 and it belongs to the Early Romantic period.