BILL CALLAHAN championed the lo-fi indie rock movement under the name Smog for more than a decade. Even in that messy subculture, he stood out. His abstract storytelling wasn’t so much sung as recited, and his sonorous voice lent a feeling of gravitas, even when he was pulling your leg. Over time, Callahan cleaned up his act, pulling back on his grinding guitar riffs and adding unusual instrumentation, which opened up his chugging rock sound. Soon after relocating to Austin in 2004, he dropped the Smog moniker altogether. Now in his forties, Callahan has moved on to adult themes (loss, yearning) without losing his cynical humor. His new album, APOCALYPSE (Drag City), is sparser than 2009’s orchestration-heavy Sometimes I Wish We Were an Eagle . A core band (including Shearwater’s Jonathan Meiburg on keys) provides the understated backing, rocking à la Smog on the front half and settling into a vibe akin to Van Morrison’s Astral Weeks for the final tracks, particularly the “Madame George”–like trance of “Riding for the Feeling” and the eight-minute coda “One Fine Morning.” Callahan doesn’t make things easy on the uninitiated. It takes time to lock in on his bizarre (yet fascinating) sense of song structure and verse, which can remind you of a child singing a rambling song made up on the spot. His lyrics are obtuse, and he has a penchant for making up words (“animaless”?). “I’m standing in a field, a field of questions,” he sings, and he doesn’t go out of his way to provide us with answers.