Pittsburgh by way of Ireland. A slight detour from the source of a music's roots can make all the difference. Case in point: Ploughman's Lunch. The Steel Town quartet has all the markings of a traditional Celtic folk outfit. As evidenced on its most recent, self-titled live recording, the boys in the band work the simple snare, the ceillann pipes and the acoustic guitar with the gusto of a Dublin pub pick-up group. But, at the core, Ploughman's Lunch takes in the world of music, with nods to soul, rock and trad folk. Indeed, the band's music is steeped in the wide-roving-but-anarchic world we saw first through the eyes of Shane MacGowan and the Pogue boys back in the day (minus some of the out-and-out punk-rock 'tude) and acts such as Black 47. Wherever you end up, so long as you're in the house with Ploughman's Lunch, it seems like a great party for music lovers. And, at Ann Arbor's acoustically-enchanting Ark (316 S. Main), prepare to stomp, weep and sing along. Call 734-761-1451 for info.