Polonaise in Gm Sample  Lesson Sample from Notebook for Anna Magdalena compiled by Bach. BWV Anhang 119. Intermediate Level. (Download) The purpose of this piece is to develop phrasing and getting the timing of sixteenth notes correctly. This lesson includes a full demonstration followed by a detailed "by ear" lesson teaching the song in two to four measure sections. When you learn without print or video you memorize the song while you learn it and develop your ability to pick out other songs "by ear."