More “Moth Radio Hour.” That’s what we’ll all be hearing, thanks to a $750,000 grant from the John D. and Catherine T. MacArthur Foundation. The Moth, a nonprofit dedicated to storytelling, is one of 15 organizations in six countries to receive the 2012 MacArthur Award for Creative and Effective Institutions, announced today. The grant will be used to expand “The Moth Radio Hour” from 10 episodes each year into a weekly series, starting in January 2013. The radio show, which features tales told from a wide range of perspectives, is presented by Cambridge-based PRX, the Public Radio Exchange, and airs on some 250 public radio stations across the country, including WBUR and WGBH in the Boston area. Among the other MacArthur recipients is the Center for Investigative Reporting, based in Berkeley, Calif., which garnered a $1 million grant.