The Kennedy Center will be doing a petting zoo/concert this weekend, at St. John's Episcopal Church in Georgetown. I know OP has already been to one, but maybe other people are interested. This one is their "Musical Opposites" program.
http://stjohnsgeorgetown.org/tickets-and-information-for-the-2013-14-georgetown-concert-series/
"In this lively program for ages 4 and older, a string quartet from the National Symphony Orchestra, featuring, Jane Bowyer Stewart, violin, Holly Hamilton, violin, Jim Deighan, viola, and David Teie, cello, engage the audience with musical contrasts, from the technical to the emotional.
Explore simple musical opposites such as high and low, loud and soft, fast and slow, then hear excerpts of the masters, Beethoven, Haydn, and Tchaikovsky. Enjoy hands-on fun with the musical instrument “petting zoo,” which gives children a chance to get up close with the instruments."