WGBH’s Brian O’Donovan brings the music of his popular, three-decade A Celtic Sojourn  program to our stage, exploring traditional and contemporary music from around the Celtic world. The show features Scottish fiddler Katie McNally (also an alumna of Groton Hill Music) with pianist and step dancer Neil Pearlman – both of Boston’s Farsan – and many other new and familiar artists of the American and Celtic traditions.