Maybe it was just the parts of town I saw, but jazz doesn’t make its presence felt in Washington DC in the way it does in Philadelphia.
Open air jazz in Washington DC
That’s not to say it’s not there. There were free open-air concerts on near the Metro Center (sic) Metro station, and on the day I was in that part of town, a very good alto-plus-rhythm quartet was playing some fairly uncompromising modern jazz (see picture). I didn’t catch their name beyond the fact that the drummer was the leader. There are also several jazz clubs, with Blues Alley and the two Twins establishments being reasonably well-known, but that’s about as far as it goes.

Overall, Washington DC gave the impression of being a city which was about power and money rather than about any sort of culture. The National Mall was certainly impressive, but any truly civilised society would have removed one of the monuments to white slave-owners and replaced it with a giant statue of DC’s greatest son, Duke Ellington.