For the first time in more than 20 years, the Des Moines Symphony will perform on opening night of the Iowa State Fair. The free, family-friendly, patriotic performance will occur on the MidAmerican stage at 6:30 p.m. Aug, 11. Broadway star Hugh Panaro, who sang at the symphony’s 23rd Yankee Doodle Pops, will sing classics of the American songbook, and barbershop quartet Vintage Sound will perform a special tribute to Meredith Willson’s Iowa classic, “The Music Man.”