My goodness; very interesting.
Off the top of my head,
1. Is it meaningful to talk about such a thing as 'political music', separate from some other types?
Yes, insofar as:
- The composer/songwriter holds a political orientation and,
- - purports to express it in their work or,
- - it is to be considered from a biographical point of view.
- A piece, tune or song not necessarily political in content or intent has been adopted as a political anthem.
It's also valid, therefore, to talk about the political in music.
. . .
So, I wonder how these composers would fit in with those definitions: Beethoven (Fidelio and the Ninth Symphony), Britten (his operas), Xenakis, Yun, and Brahms (Academic Festival Overture)?