What do you mean by "mainstream" and "non-mainstream"

The mainstream of water is opposite to the "tributary".

The main trend of things has nothing to do with the number of people. Guo Moruo's The Mission of New Literature and Art: "Writers get resources from life and the masses extract from literature and art. Although this interaction is not obvious, it is indeed a mainstream in new literature and art." Zou Taofen's Plain European Bureau and Bright Far East: "Our hard work is in line with the most progressive mainstream in the world." [ 1]

3. Dominant or center (case) corresponds to tributary and lateral flow.

Mainly neutral, such as "mainstream media"; Sometimes it contains satire of "temporary gain", such as "mainstream economist".

Classical, Middle Road and Jazz without electro-acoustic treatment since the 1920s. At first, the innovative performance styles such as pop music, free jazz and modal jazz were not included in the mainstream music, but with the passage of time, the mainstream also made some concessions to the innovative style.

5. The shipping department usually refers to the water flow with large surface velocity that determines the main flow direction in the river channel as the mainstream.

6. The mainstream of society has made the normal things accepted by the public conform to the development law of society or things.