Where to go dancing? (Boston)

Hi everyone!

I'm new in town (just moved here to live with my Italian boyfriend who works at Harvard) and I love dancing! So I was wondering whether any of you know any good places to go dancing at night. I prefer partner dancing, but any style goes: salsa, folk, rock 'n' roll, lindy hop, tango... I'm not so much looking for classes as for a place (bar, ballroom?) where I can just go and dance a bit. Close to Davis square, Somerville would be a plus, but isn't necessary. Any ideas?

Thanks in advance!

Clara