Some free online collections:** collections.si.edu/search/results.htm?q=&fq=online_visual_material%3Atrue&fq=online_media_type%3A%22Images%22&fq=culture%3A%22Chinese%22&fq=object_type%3A%22Paintings%22&view=list&date.slider=300s%2C1800s
- Smithsonian collection at a search for Paintings before 1800. Drill down further by "topic" e.g. "Mountains" or "scholar"
Unclear legality:
- www.ibiblio.org/chinese-music/html/traditional.html has many tracks which appear to be rips from vinyl records due to the scratching sound, and unclear attribution