由于五线谱中的线和间只能表示钢琴白键上的音,如果要表示黑键上的音,就需要用到一些临时记号——如升号和降号。升号表示一个音符升高半音,降号则表示降低半音。如果一个音在同一小节单位里有多次重复,则这些临时记号对重复的音同样有效。要让一个音回到原来的音高,则需要使用还原记号。 Since lines and spaces in staves can only represent tones on white keys of a piano, temporary marks such as ascending and descending numbers are required if the tone on the black key is to be represented. The ascending sign indicates that a note is raised in semitones and the ascending sign indicates a decrease in semitone. If there is more than one repetition of a tone in the same measure unit, these temporary marks are equally valid for repeated tones. To make a tone back to the original pitch, you need to use the restore mark.