Start flexing your booze-disguising muscles and port-a-picnic over to the National Gallery of Art’s Sculpture Garden tonight for Free Jazz nights. Starting tonight, from 5-8:30 p.m. you can enjoy live jazz music and the company of far too many strangers. Put this on your weekly calendar, but maybe contemplate sneaking out of work 15 minutes early and getting there as soon as possible. After 6 p.m. there is nary a green patch to put your bum on, honest. If you do get there early, you can also pop in line for a delicious pitcher of sangria before everyone and their mother joins you.