On Heartless Bastards’ fourth album, singer-songwriter-guitarist Erika Wennerstrom and her newest set of backing musicians continue to follow the mud-stained heartland highway that connects early Neil Young records to the latest Kings of Leon disc. Perhaps because producer Jim Eno also drums for another Austin band, Spoon, the rhythms are sharper than ever, and new second guitarist Mark Nathan helps Wennerstrom come up with guitar breaks that can sing as well as wail. But mostly the singing is left to Wennerstrom’s peculiar vocals, the group’s main attraction and distraction at once. Her delivery works on the uptempo first half, including the bittersweet return to her native Dayton, Ohio, “Skin and Bone.’’ But the ballads that dominate the disc’s second half give her too much room to savor her elongated vowels and gulped consonants, contorting the words so much their meaning becomes indistinct. Such musical mannerism has its place in rock, but on this rutted route it’s beginning to sound lost. (Out tomorrow)
ESSENTIAL “Skin and Bone’’Heartless Bastards perform at the Middle East Downstairs Feb. 23.