Violinist Augustin Hadelich played a Stradivarius for years, and now plays a del Jesu, which he says has a more even tone. It certainly shined in his recent performance of the greatest American violin concerto ever composed, by Samuel Barber in 1939. APR Sunday live broadcast host Chris Mohr talks with him about his new violin, and the uniquely beautiful violin concerto of America's own Samuel Barber.