Use a center table to divide two spaces. Oversize rooms can be just as tricky as small rooms; they can feel cold and cavernous. The goal is to bring them down to a human scale and encourage comfortable gathering.
Although not an official "concert hall" this place is breath taking. You are looking at Ely Cathedral in England. It does have a little fame attached with being mentioned in novels and filmed in movies (most recent being "The King's Speech"). This place is full of history starting before the 12th century.