Curated by WGBH’s Brian O’Donovan and harpist/composer Maeve Gilchrist, the 4th annual Rockport Celtic Festival celebrates the music of both the Celtic and French diasporas in Eastern Canada, with musicians and storytellers performing throughout the weekend. Most shows take place at the Shalin Liu in Rockport, and highlights include a performance by the duo Rakish on September 14 at 7:30 p.m., a traditional ceilidh on the 15th at 9:30 p.m., and a “pub” sing on the 16th at 1 p.m.