I highly recommend Louis Arnold. He's based in Lunenburg, MA, but teaches at the Minor Chord in Acton, MA.
I took lessons from him for 5 years many years ago, and am hoping to hook back up with him when I can swing it.
He was affiliated at that time with the New England Conservatory, and he's a graduate of the Longy School of Music.
Great guy, and a very open-minded, well rounded musician who also excels in many other genres.
His contact info here: