The phrase "art gone on" can be used to describe a piece of artwork that has become outdated or no longer relevant. Synonyms for this phrase include "obsolete art," "outdated art," "antiquated art," and "archaic art." These terms suggest that the artwork is no longer appreciated or valued in contemporary culture. Other synonyms, such as "vintage art" or "retro art," imply more positive connotations and suggest that the artwork is now considered nostalgic or trendy. Ultimately, the interpretation of "art gone on" will depend on the context and perspective of the artist and the viewer.