A quartet of gallery summer group shows

Gallery summer group shows may have roughly the same motivation -- filling the space during a slow season for sales -- but they take many forms. Some revisit earlier exhibitions, while others feature work that's new or just didn't fit into previous lineups. Overarching themes are not required but can be ambitious. Thus, Hemphill Fine Arts' "Artist-Citizen, Washington DC," in which eight artists and two collectives enter the civic realm.