Rush’s dystopian sci-fi concept album 2112— yes, the one with the dedication to “the genius of Ayn Rand”—turned 40 earlier this year, and that milestone birthday has touched off the usual flurry of nostalgia and introspection. The Canadian prog rock trio will release a lengthy, lavish reissue of the LP, one of its most enduring, on December 16 in ”a variety of formats.” The standard two-CD/DVD package will include the original 1976 album, newly remastered at Abbey Road Studios, on one disc with the second disc devoted to “live outtakes” and freshly recorded covers by such luminaries as Alice In Chains and Billy Talent. Dave Grohl, meanwhile, is teaming with Taylor Hawkins and Nick Raskulinecz for a new version of “Overture.” And what’s on that DVD? For one thing, a 1976 Rush performance at the Capitol Theatre in Passaic, New Jersey. There are also some explanatory featurettes on there, plus a video for Grohl’s “Overture” remake.