Name that patriotic Mainland song

I heard a terrific (even spine tingling) song in a Canadian-made documentary about the rise of capitalism in China. The doco was called something like China Red. The song was presented at the end of the show, and was derisively described as being reduced to a showpiece in a Hong Kong nightclub act.
The same song turned up in one the middle of one of my favourite soft porns, Unforgetful Holiday. It is sung on karaoke by the main characters, mainly a mainlander.
Then it also turned up in a long documentary about the people who organized and participated in Tianemin Square, a few years after the event.
Anyone have any idea what this song is?
It is clearly a very well-known song.
The same song turned up in one the middle of one of my favourite soft porns, Unforgetful Holiday. It is sung on karaoke by the main characters, mainly a mainlander.
Then it also turned up in a long documentary about the people who organized and participated in Tianemin Square, a few years after the event.
Anyone have any idea what this song is?
It is clearly a very well-known song.