Robert Grubb learned the bagpipes in the early 1980s when his Celtic marching group needed players. Around St. Patrick’s Day is his busiest time, but he’s called upon all year to lend ceremonial skirling at graduations and funerals. The retired engineer and his wife, Wendy, belong to a host of Celtic heritage organizations, and he plays at the Irish House every Tuesday with a group called Kilts of Many Colours. Otherwise, Grubb practices at home with doors firmly shut. “I’ve told people it’s loud and obnoxious,” he admits, “but you can really have a lot of fun with it.”