Harmonica maker Hohner fine tunes its international supply chain. By Chris Dupin Hohner, the world-famous manufacturer of harmonicas and other musical instruments, still makes many of its mouth harps at its factory in Trossingen, Germany “the old world way,” in which products are hand-tuned and assembled, said Scott Emmerman, director of marketing and sales at Hohner Inc., the company’s U.S. subsidiary. But like many manufacturers, Hohner now sources...