The Drift hasn’t always played mellow, ambient-laced krautrock. Before the trio’s former horn player died of cancer, the group rocked out in the realm of epic jazz. Now the Drift’s tactile swirl of meandering guitars, infectious grooves, and warmly glowing keyboards provides an instrumental soundtrack to more ruminative emotions: longing, doubt, confusion, wonder, dread, and faith. Blue Hour isn’t a showy album. Rather, it’s patiently built from bittersweet memories and hope for a sublime future.