Watching the evolution of Greensky Bluegrass during the past decade has been an inspiring, rewarding ride. The scrappy quintet from Kalamazoo, Mich., hit their stride in 2011, boiling down organic bluegrass jams into the expertly crafted songs of Handguns. Three years later, If Sorrows Swim is an even more accomplished record. It’s an intense, 12-track ride of ragged harmonies, infectious melodies and mesmerizing picking (banjoist Michael Arlen Bont is the band’s secret weapon). Guitarist Dave Bruzza brings four songs to the table, and his more traditional, country vocals and melodies provide familiar ground; it’s mandolinist and singer Paul Hoffman’s offerings that veer into new territory. His aching, impassioned vocals are immediately arresting. Opener “Windshield” finds him howling at the moon that, “Someone better hide the children/I think things are getting out of hand.” Indeed they are, and it’s never sounded better.