Blitzen Trapper This is the second time in as many weeks I'm coming to the defense of '70s plains rockers, but what the hell take my Rock Critic card. Blitzen Trapper, while unceremoniously lumped into the whole forest rock conflagration when the band first emerged a few years back, has taken some heat for its new record, Destroyer of the Void, which is curious since it just came out a few days ago. While Midlake got lauds for their "Fleetwood Mac" (Van Occupanther) record and lumps for their latest "Fairport Convention" platter, The Courage of Others, The Trappers have always played an original blend of folk, rock and cosmic slop so what if the new record sounds a little more epic? So what if it hints at Kansas and America? (The phrase "wayward son" is indeed used.) Folk and progressive rock have always been fair bedfellows, despite what some unnamed larger-than-life critic types might try to tell you, and hardly anyone these days does it better. This Trapper's a keeper. With The Moondoggies. $12-14, The Casbah at Tremont Music Hall, www.tremontmusichall.com.