Bach grew up with a passion for music, and in addition to studying with his elder brother, he also joined a church choir. But he was not satisfied with his desire to learn, and took advantage of the quiet of the night to copy music alone by moonlight. He often lost track of time because he was over-involved in the wonderful world of music, not realizing that the night was fading, and often waited until the morning sun broke through the sky before he put the sheet music back with great reluctance. Because of the long time sleep deprivation, his body is getting thinner and thinner day by day. When his brother found out that he stayed up late every night copying music, he reprimanded him angrily and sternly, telling him that he should study music step by step and should not be over-ambitious, and that he should not turn day and night upside down, wasting his body. Bach accepted the advice of his elder brother.