Marion County native Jason Brown will be at the Knoxville Raceway Friday, playing a country music concert presented by the Knoxville Hospital & Clinics Foundation and with Hy-Vee.  That’s according to hospital spokeswoman Katrina Nelson.  She says advance tickets are $10 for adults $5 for kids ages six to 14 with kids five and under free, and tickets at the door are $15. The show will go on rain or shine, and in the event of rain will be held in the Show Barn on the fairgrounds.  Nelson says tickets are available at Iowa State Savings Bank, The Next Chapter, and Knoxville Hospital & Clinics or by calling 842-1418.