It is quite some time since I spent any significant time in the DC area, so I will let someone else answer your specific question. It is quite a schlep from DC to Alexandria, though, so you may be better off looking for accommodations in the latter. There used to be an Embassy Suites in Alexandria right across the street from the Metro (light rail) line into DC, if you want to visit museums and do other tourist stuff, and that's not too far from the Masonic Center.

I'd suggest the Greater Washington Folklore Society site for folky info.