On December 5th at 8pm, NBC will broadcast a live production of “The Sound of Music” “for a new generation,” featuring Carrie Underwood as Maria, “True Blood” star Stephen Moyer as Captain von Trapp, Audra McDonald, Laura Benanti, Christian Borle and others. The production, which is based on the Broadway musical, comes from executive producers Craig Zadan and Neil Meron (“Smash,” “Hairspray,” “Chicago”). It could be read as an attempt to cash in on our renewed love for musical numbers, be they in singing competitions or “Glee,” but there’s something so ill-advisedly old fashioned about this whole idea — live! — that it’s kind of charming. Here’s the trailer for NBC, which is, for obvious reasons, made up of interview and rehearsal footage.