Canonic Variations on "Vom Himmel hoch, da komm ich her", BWV 769 (in the sequence of the autograph) - Variation I: In Canone all'Ottava (卡农变奏曲“从天堂我来到人世”，作品769 - 变奏1 - 在音符下面的指示符号) (in the sequence of the autograph)