It’s undoubtedly something of a coup for Feile An Droichead to have persuaded Altan to play at An Droichead, a much smaller venue than is customary for the legendary group. Few trad outfits can boast the sustained activity and international appeal of Altan, who have been thrilling audiences around the world for three decades. The band will be celebrating its 30th anniversary in 2017, but in truth, an Altan concert at any time is a celebratory event and tonight is no different. First up, however, is Kern. The Louth trio has been together for nearly three years and its dashing…