Every Sunday afternoon, drummers and dancers gather to perform at Meridian Hill park.
This is a fun afternoon activity, not to mention full of great photo ops.
If you aren't familiar, check out this Washingtonian article and video.
The drummers officially start at around 3:30, but I'm scheduling later for better light. They usually go until nightfall.
When you arrive at the park, just follow the sounds to the drums. I'll be right at the base of the Joan of Arc statue in my black Meetup t-shirt.