If you are not a member of a band or jazz ensemble, open mikes can serve as a performance outlet and they are a good place to connect with other musicians. Good sources of information are The City Paper, and the Washington Post style section.
The Songwriters Association of Washington DC
http://www.saw.org/
OpenMikes.org
http://openmikes.org/calendar/DC and
http://openmikes.org/listings/nearzip.php?zip=20009&proximity=25
Jammin’ Java in Vienna
http://www.jamminjava.com/index2.php
Jaxx’s Nightclub in Springfield
Find contact and calendar information at
http://jaxxroxx.com/
An additional source for area venues is MusicDC.
http://musicdc.com/
If your band is struggling to be heard by a wider audience and industry insiders, you should also search regularly online for appropriate music festivals. You’ll need a great demo, some festivals may require DVDs. Check each festival. There is usually an entry fee, and like all auditions in the arts, you may or may not get the gig. Still if you do, the payoff can be great.