John P,
       Joni Mitchell wrote and sang "Big Yellow Taxi", a song concerned with environmental issues, relevant to many people at that time. Later Martin Carthy sang a song concerned with the Falklands war, also an issue relevant to many people at that time. There are songs being written and sung concerning contemporary issues, by numerous people , all the time. Surely, in those instances, do they not all come under the same "genre"?