The Worcester Art Museum will be free in July and August, courtesy of Barry Morgan.
From the Globe article:
In the next decade, Waschek hopes to increase attendance to 200,000 a year. He also wants to consider making the museum free permanently, though he is not sure if that is possible. The museum receives no public money to offset lost ticket revenue.
I hope someone with a better knowledge of history can confirm or deny this, but I believe when the WAM previously had those kinds of attendance numbers, there was no admission fee. (I know there was no admission fee in the 1960s; does anyone know when that changed?)
Nicole, Worcester 
Evidently we don’t need a press conference. Thanks Nicole!
The Philadelphia Art Museum offers a ”Pay What You Wish All Day” on the first Sunday of each month. I happened to be there on such a Sunday and the place was packed. It seemed that most patrons were paying in the $5-$7 range, and that was fairly late in the afternoon, with only 2 hours of viewing time until closing. We paid $5 each and had we had 4 or more hours to view, we likely would have paid more. There was a perceived benefit and we were willing to pay. Great marketing plan!
Btw, thanks for the info!
I think the MFA accepts donations during its free Wednesday evenings as well.
When we visited the Clark Art Institute a couple of years back, it was free (as it is during most of the year); it made us more inclined to buy a lunch there and visit the gift shop, as a way of showing our thanks.