What was the state of music in China during the Cultural Revolution? Was traditional Chinese music (like Peking Opera) shoved aside from more Western-sounding works? Were the musical works of Madame Mao seen as revolutionary or conservative?

I only know a bit about this, but I hope you find this useful

Generally speaking: Anything that was western, or considered old-fashioned was destroyed. Similar with the suppression of non-revolutionary music. Revolutionary songs (songs with nationalist rhetoric) were a popular form of entertainment for people who participated willingly in the cultural revolution.

We also had Revolutionary Operas. Basically they were Chinese operas, but with national socialist rhetoric, rather than traditional plots. I don't know anything about the musical differences here, as I mentioned I haven't done any long term research on nationalism and music (nor would I care to, it tends to lead to pretty dark places, a la the whole Wagner being a nazi thing).

After the cultural revolution we see more western influence in the music, one song in particular "Moon represents my heart" marks an important turning point in chinese musical aesthetic away from revolutionary songs and operas (at least in public), there was definitely a black market for western and traditional music (smaller scale dissent was not uncommon in the cultural revolution).

Hope this helped :)