The bird threw me off balance for several reasons as it looked Raven-like but the tail shape was far from wedge-shaped, and overall it looked small and puny for that species. Although pretty lousy, and taken against complete cloud cover in dull early morning light, the photos also emphasized what I'd seen overhead. Overall, the bird recalled a Chihuahuan Raven a species that I've seen hundreds of times on trips to Texas and Arizona but as far as I'm aware there's no precedent for vagrancy in that species, especially to the north-east.
Naturally, the easy option would be to pass it off as an odd looking Common Raven. On the other hand, the remnants of Hurricane Patricia passed through New England late last week, so how about a disorientated Chihuahuan Raven showing up and trying to work its way back to the south-west? Of course, it's stretch to think about such things, and "remarkable claims require remarkable evidence", but then again, who looks at Ravens?
unidentified raven - Main Road, Gill, Franklin Co., MA. November 2nd, 2015.