Jacobs often played the harmonica on records by others in the Chess stable of artists, including Jimmy Rogers, John Brim, Rocky Fuller, Memphis Minnie, the Coronets, Johnny Shines, Floyd Jones, Bo Diddley, and Shel Silverstein.
A few months after returning from his second European tour, he was involved in a fight while taking a break from a performance at a nightclub on the South Side of Chicago.