An Cuigear, Friday, June 7, at the Rocky Mountain Center for the Musical Arts (200 East Baseline Road in Lafayette), is an Irish-music five-piece that hails from Boston. But local lovers of Emerald Isle music will be familiar with the group's founders, Mathew and Shannon Heaton. Before moving east just a few months ago, the Heatons headed up one of Colorado's better Irish groups, Siúcra, a trio that featured the singing of Beth Leachman and an earthy sound that matched fierce craic with instrumental prowess and buckets of emotion. An Cuigear ("the five of them" in Gaelic) joins Matt (guitar) and Shannon (flute) with Boston-area hotshots George Keith (fiddle), Dave Cory (banjo) and Sean Gannon (accordion). The quintet has moments of staunch traditionalism, but it also incorporates grooves, giddy vocals and inspired jamming while honoring Ireland's musical past. Local musicians interested in upgrading their chops can take advantage of An Cuigear's arrival: On June 6-8, the musicians will be giving lessons at the Rocky Mountain Center. (Call 1-617-628-3374 for lesson details and times.) All told, the Heatons will blow back into town in an action-packed homecoming that should thrill Irish-culture fiends.