Delivering bluegrass versions of Grateful Dead, Tom Petty, and the artist's own classics with harmonious singalongs and a hint of psychedelia, revered singer/songwriter/instrumentalist Keller Williams brings his concert event DeadPettyKellerGrass to Maquoketa's Codfish Hollow Barn on June 28, this "one-man jam band" hailed by AllMusic as "“an utterly unique performer whose musical eccentricities don't keep him from being immediately accessible.”