“It used to be darker, then it got lighter, then it got dark again,” Bill Callahan (Smog) sings over swollen strings on opener “Jim Cain,” and since his ex, Joanna Newsom, began appearing with SNL’s Andy Samberg last year, it’s easy to write off the album as one big breakup bitchfest. As promised, Callahan’s second release under his given name returns to the emotional cavity-tongueing of his earlier work, after 2007’s Woke on a Whaleheart’s sort-of flirtation with happiness. “Eid Ma Clack Shaw” (which reappropriates the “Psycho Killer” bass line to unbelievably gloomy effect) even insists “love is the king of the beasts, and when it gets hungry it must kill to eat.” But Eagle thankfully retains and even expands on Whaleheart’s sophisticated orchestral swells and chorale arrangements rather than reverting to the outsider experimentation (critic speak for “seemingly structureless and often unlistenable screwing around on out-of-tune instruments that I’m too scared to dismiss entirely because I suspect Callahan’s a hell of a lot smarter than me”) that distinguished so much of his Smog output. Eagle is a near-perfect blending of beautiful instrumentation with Callahan’s poetic lyrics and limited though extremely soothing baritone, and a definite career highlight — a “breakup album” in the Blood on the Tracks tradition. Besides, Callahan’s mantra, “It’s time to put God away,” repeated for the better part of 10 minutes in closer “Faith/Void,” suggests he’s sweating bigger stuff than that “Dick in a Box” dude.