Simple notation refers to simple notation. There are two kinds of letter symbols and number symbols. It originated in France in the18th century and was improved by the Germans, so it became what it is today. The so-called music score generally refers to digital music score. Digital notation adopts the method of moving roll call. 1, 2, 3, 4, 5, 6 and 7 represent the seven basic levels in the scale, with the pronunciations of do, re, mi, fa, sol, la and si, and the rest are represented by O. The sound length name of each number is equivalent to the quarter note of the staff.