Furchgott Sourdiffe Gallery is currently exhibiting 18 artists whose styles and mediums vary significantly. What they have in common, according to the gallery, is an “intense focus on their subject matter.” Though that quality would seem like a given — all artists are focused on their work, no? — calling it out does pique one’s curiosity. Visitors to the Shelburne gallery can experience this creative intensity firsthand, whether it’s expressed as sunlight in a landscape, an interior fantasy or a particularly meditative abstraction.