What kind of historical materials does the song belong to?

Written historical materials.

Poetry belongs to written historical materials. Although the content of literary works is fictional, it can often reflect people's lives, thoughts and concepts at that time, which is helpful to the study of cultural history, ideological history and social life history.

Written historical materials refer to things that can be used as the basis for studying or discussing history. Historical materials are generally divided into primary historical materials and secondary historical materials.