Many people love music, but what is it? Generally, music is an art form in which the medium-sound is organized in time. The development of music among humans must have taken place against the backdrop(背景)of natural sounds, such as birdsong and the other sounds for animals to communicate.
Music can be divided into genres(流派) and sub-genres(分支)，although the dividing lines and relationships between music genres are often subtle（模糊的), sometimes even controversial. However, just as the saying goes "one man's meat is another man's poison", no matter what kind of genre one likes, the important thing is that he can get satisfaction from it.
In general, music is composed and performed for many purposes: aesthetic（有关美的，审美的) pleasure, religious or ceremonial purposes, or just as an entertainment product for the marketplace.