Boston, Providence, Cambridge: HELP

i'm going to be making a short visit to Boston, Providence, and Cambridge in
a week (i'm staying in Boston, so i'll probably just visit Providence and
Cambridge for a day). i was wondering if any of you could send me a list of
interesting music stores in these areas, as well as a list of good shopping
districts and historical sites WORTH seeing. it'd be much appreciated, as
i'm having a hard time organizing the information i'm trying to gather for
the trip.

and oh - i probably won't bring that much money with me, so you don't have
to worry about me buying all the U2 merchandise from your favorite music store.

thanks in advance,

~yohan
http://www.geocities.com/soho/lofts/2527/exit.html