If you're in town for the conference and looking for some good live music, there's heaps of places to check out.  The easiest to find are jazz clubs or punk clubs, the two things DC historically does best.  I'll give you a quick summary of the DC scene.

The U St/African American Memorial/Cordozo metro stop is walking distance to a bunch of great venues, including Black Cat, a gritty punk venue (www.blackcatdc.com) which the week of the conference will have Dan Deacon on Wednesday, Grupo Fantasma and a Big 80's dance party on Saturday, and Cloak/Dagger on Sunday.  That metro stop is also RIGHT near the world famous 930 club (www.930.com) which sadly only has two shows listed right now for that weekend, those being Abba on wednesday and thursday, and Fish on Sunday.  That metro stop is right near the Velvet Lounge, a small punkish lounge, also, which always has great local music (www.velvetloungedc.com) as is the DC9 if you like really ratty really small dives.  Also, U stree is famous for it's excellent Jazz Clubs.  You can easily walk up and down just to find a place to sit up and sip, listening to good tunes.  Bohemian Caverns is DC's largest jazz club and has had the biggest names in jazz play there (Duke Ellington, Louis Armstrong, Miles Davis, John Coltrane, etc.) so that's definitely a safe bet (www.bohemiancaverns.com).  The other jazz bars on U street are Twins Jazz (www.twinsjazz.com) U-Topia (www.utopiandc.com) and a host of others.  Little farther down is Saint Ex Cafe, which is pretty small, and amazes me that they can fit even a drumset in there,

Adams Morgan area is not exactly next to a metro stop, but there are enough bars and clubs on the 3 or so blocks that incorporate it that it is easy to spend the whole night there.  In Adams Morgan, Asylum has live bands with no cover on Fridays (www.asylumdc.com), and Club Heaven (located right above Club Hell) has the city's best 80's dance party every Thursday. 

H Street, the so-called Atlas District, is just recently blowing up in NorthEast.  The Rock and Roll Hotel (not actually a hotel) (www.rockandrollhoteldc.com) is a quaint little place which hosts nationally famous indie rock acts and homegrown heroes.  The actual "venue" part of it is small, so make sure you get there early to see any of the bands, and don't forget to check out the upstairs bar with poster relics all over the walls and flying guitars above your head.  Shows playing during the conference haven't been posted yet.  Also on H Street is The Red and Black (www.redandblackbar.com) which is a small place which holds local artists in a New Orleans style setting.

This is just the tip of the iceberg, there's tons of places to go in the city without spending a lot of money.  This should get you started.