Hi Ms. Stephanie,
VA Bar provides live Jazz on regular basis, but i never have been there yet. On X'mas eve, i was in my favorite bar Hot Cat Club which is not too far from VA and after that i was in School (some kind of a mini disco where they play punk instead of techno/house).
And School is in the same lane where VA is (Wu Dao Ying).
But i have been once in VA bar just for a coffee, inside the cafe it is quite cozy and chilling but it was too early for their live set. But i can imagine that VA may be a very nice venue for live Jazz. In fact there is a Jam Session tonight: http://www.douban.com/event/13147892/
I will be dine out with friends next at the Yunnan Place next to Hot Cat Club, after that no plans. But i guess the Jam Session in VA bar wont last that late.
My favorite Jazz place in Beijing still is East Shore (south side of Houhai near the bigger Stone Bridge)