Revered for contemporary-folk hits including "Words," "The Stable Song," "Big Black Car," "If I Go, I'm Goin," and "San Luis," the South African-born singer/songwriter Gregory Alan Isakov headlines an August 14 concert at Maquoketa's Codfish Hollow Barn, the artist's most recent recording Evening Machines lauded by Paste magazine as "an album of small intentions with a grand sweep, intimate and boundless at the same time."