Mainstream¹ is, generally, the common current of thought of the majority. It is a term most often applied² in the arts (i.e., music, literature, and performance). This includes:
something that is ordinary or usual;
something that is familiar to the masses;
something that is available to the general public.

Note:
Mainstream用来形容目前大部分人的认同的东西，通常用来形容艺术，例如音乐、文学和演出。

它的含义还包括：
1. 平凡的
2. 大众熟悉的
3. 适合大众场合的