The Parks and Recreation Department is sponsoring Sunday evening concerts on the town common, with Nightwork, a blues band from Ashland, performing this weekend, and shows continuing into August. The concerts begin at 5 p.m., weather permitting, and offer a variety of music. Residents can spread a blanket on the common, where refreshments will be sold. Stilburnin, a Southern rock bank from Millbury, will perform next Sunday, and an oldies band, the Reminisants, is scheduled for July 29. The series will conclude with the Hopkinton Concert Band performing on Aug. 5.