Camden Opera House's occasional series of free performances in its intimate third-floor listening room returns with Darlin’ Corey. Award-winning fiddle and singer Erica Brown teams up with singer-songwriter and multi-instrumentalist Matt Shipman; and Portland’s fave bass player, Kris Day, to blend folk, bluegrass and old-time music.Doors open 7 p.m. Doors open 7 p.m. to the opera house’s street-level elevator lobby, 29 Elm St. Attendees take the elevator to the third floor, whose windows will be outlined with blue rope lights for the evening. The Blue Café seats around 50, with more room in the adjacent lounge. There is no admission charge; donations for the sponsoring Community Arts Fund are welcomed.