Four years after her celebrated collaboration with Robert Plant on Raising Sand, Alison Krauss slips back into her bluegrass comfort zone on this sleepy little album. With the MOR settings stuck on tasteful melancholia, Krauss’ heartache vocal is as pure as the prairie wind but she’s always lacked the grit of say, Maura O’Connell. Paper Plane does get some grit in its engine with Dustbowl Children, a banjo-propelled Depression lament sang by stout-voiced Union Stationer Dan Timinski. The playing is superb throughout and covers of songs by Jackson Browne (My Opening Farewell) and Richard Thompson (Dimming of the Day) are well judged. However, we’d rather Alison had got busy raising more Sand and not just The Sandman.