July 2, 2007 | 12:00 a.m. CDTIn a fluorescent-lit, poorly air-conditioned room inside the Unity Center in Columbia, 12 brown folding chairs are arranged in a circle. Capturing the sounds, audio recorders, ranging from Sony digitals to old-fashioned tape players, are placed randomly on the blue and gray carpeted floor. Four students, each double the instructor, Brian Hart’s, age, take their seats and play their tin-whistles. After a few minutes the music stops and Hart takes a deep breath. He then looks at his eager students.