On special invitation, four Bulloch County men will travel to Pyongyang, North Korea next month to perform in the Democratic People’s Republic of Korea during their Spring Arts Festival.Bill Coen, David Brinson, Paul Moller and Jay Stansbury , members of “Sons of Jubal,” an 150-member all male chorus and orchestra based in Atlanta, plan to leave April 10, Coen said. They will return after a five-day visit.Sons of Jubal will be one of the largest musical groups of Americans ever to enter the Democratic People’s Republic of Korea, said Eddy Oliver, communications director for the group.The Sons of Jubal was founded in 1954 and consists of volunteer professional musicians, church musicians, educators, and institutional leaders from all across the state of Georgia, he said. The group was invited to attend and perform during the festival by Korean officials who heard Sons of Jubal at Stone Mountain a few years ago, according to Coen.“We’ve been working on this for two years,” he said.