Op.51 G flat Major Impromptu of Frederick Chopin. This piece is frequently taken up at piano classes and also most of the pianists have this piece in their repertoire. It is important for performers to have an idea on armony and formal structure in order to gain different advantages and interpretations. Main scope of this study is to take up Chopin's Impromtu in terms of harmony and formal structure and better understand Chopin’s inner world. It will also contribute to the better understanding of Chopin's music and will provide different perspectives for performers