Alison Krauss was signed to Rounder Records in 1985, the same year Coca-Cola discontinued its “classic” flavor in favor of a new mixture that famously fizzled. It’s only a wild guess, but perhaps the then-teenaged musician took note of the massive marketing goof and vowed it would never happen to her. This would explain why she’s been bottling the same formula, more or less, for most of her phenomenal career. Paper Airplane is a neatly creased, lightweight affair so similar to her and Union Station’s last studio effort that it could be from those same early-2000s sessions. Aside from bandmate Dan Tyminski’s American-roots turns, there are fewer diversions this time from the restrained, often introspective fare Alison favors, including the regrettable omission of the stirring devotionals that have graced her past works. Only the sublime “Dimming of the Day” offers a peaceful respite from the disc’s themes of emotional restlessness and unease. But if it’s a finely brewed, bittersweet flavor you crave, this classic is still the real thing.