Around this time of year near the Arctic Circle, blueberries grow under the late-burning sun with an urgent intensity. Dogs bark at midnight shadows. The half light fingers bedroom curtains and infects dreams with restlessness. "White Nights," the theme of this year's music festival presented by the Chamber Music Society of Central Virginia, features works spanning the Baroque to post-modern eras by composers from Estonia, Russia and the Scandinavian nations. Is the music influenced by the immoderate day, and later in the year, the endless night? Finnish composer Kaija Saariaho, whose 1992 work "NoaNoa" for flute and electronics will be performed Monday by Mary Boodell, has said of that piece, "I wanted to write down, exaggerate, even abuse certain flute mannerisms that had been haunting me." Concerts are May 13 and 16 at 7:30 p.m. at First Unitarian Church of Richmond, May 14 at 12 p.m. at the main Richmond Public Library and 7:30 p.m. at Wilton House. The Saturday afternoon concert is free; others are $5-25. Visit cmscva.org or call 519-2098.