Gifted with a supple baritone and brooding gravity, Bill Callahan has been refining his stark songwriting since the early '90s, when he shifted gears on a regular basis as Smog. His deadpan bleakness made Smog entries like “Dress Sexy at My Funeral” and “Cold Blooded Old Times” bitterly funny indie rock, while subsequent albums under his own name pursued a more spacious and sustained feel that suited such long-favored subjects as birds, trees, rivers, and other quiet marvels of nature. But even his solemn questing through pastoral Americana has had its share of quirky detours, like the rambling pop-culture references of 2011's “America.”