Hi again mcmoo. Try this site for local & beyound local folk music stuff.
http://www.music-for-robin.org/nov1.htm
Also go here to the Boston Globe's calendar section, there very supportive of folk musci in the area & update this as time get closer.
http://www.boston.com/goingout/activities/folkconcerts.shtml
Here are some bars that have sessions;
Burren in Somerville (nightly)
Paddy Burke's near North Station (Wed.-singer's session)
Mr.Dooley's - Downtown Boston
Druid in Cambridge (Fri.?) (call 617-497-0965)
Matt Murphy"s in Brookline on Harvard Av. (Thrus.?)(tel # ?)
Brendan Behan in Jamaica Plain (time?)(617-522-5386)
Press Room in Portsmouth NH about an hour north of Boston, it's a mix of Irish & bluegrass with a strong focus on lots of real good singing& that leans a good bit towards shanties.
When calling make it clear that you're looking for info on a Trad session, otherwise you'll get anything for an open mike to stand up comedy act to get you in the door
I stayed to the times you'll be here. If you'd like contact me before you get here & maybe we can get together for some music, though I don't get the chance to get out to often.
Have a great visit in our musical city. Barry