That photo is from Ronda Matson's website; Ronda is an acoustic guitarist (along with other stringed instruments) who performs mostly in Massachusetts. She has a lot of photos on her website of her musical endeavors and venues. The Bar in question is The Firefly, according to Ronda Matson. The caption maintains that "Larry Dubinsky runs the restaurant show;" the other fellow in the photo is the bartender.
There is a Firefly's BBQ and Grill in Framingham, MA. This is not close to Woodstock-CT, but doable. There is also a Firefly's in Marlborough which sounds more likely (same organization). But both seem to have open-mike nights on Wednesdays (subject of the photo), so I am not sure...