For data regarding artworks, collections, galleries or museums, state funding or involvement in the arts, art history, and aesthetics.
There's been a lot of activity on the art open data front recently:
Here are some examples of the kinds of things you can do with art open data:
2 datasett funnet.
Various RDF datasets from the National Gallery. Some appear to be under an original-BSD-style licence, which I believe amounts to an attribution licence.
A screen-scraped RDF/SPARQL database of artworks in various UK government collections. See here for details of how the data was assembled:...