Well-known songwriter Dave Alvin will play at 7:30 p.m. Tuesday, April 26, at Blue Hill Town Hall in a special unplugged showcase. Alvin’s latest album, “Ashgrove,” his first on the Yep Roc label, has gained critical acclaim. The Grammy winner is known for his work with the Blasters, as a guitarist on dozens of recordings and as a producer. Special guest for the evening will be Jay Peterson, the Swedish Cowboy, formerly of “Prairie Home Companion.” For information, call Joel Raymond at 667-3618 or go to www.davealvin.com.