Hi Joey,
Here’s a google map of the towns in Massachusetts with cultural districts designated by the Massachusetts Cultural Council as of 2014. Besides Gloucester, Barnstable now has 2 cultural districts.
If you’re traveling in MA–or anywhere across the US that has cultural district designations–they’re a good place to investigate ahead of time for planning.
The summer Butterflies exhibit at the Berkshire Museum that includes Kim Smith’s work is nearby 5 western ma cultural districts and ideally situated for visiting Tanglewood or whatever Berkshire art and trail you envision.