The Commission on Public Art is holding Louisville’s first national conservation  conference, “The Power of Public Space,” on Sept. 14-15. On Friday, the panel discussion is on  ”Stewards of Cultural History: How to Evaluate and Refine Louisville’s Public Art Collection” is at  Metro Hall Gallery from 5-7 p.m. “The Importance of the Artist’s Voice” is on Saturday from 9:30 a.m.-1 p.m. at the Speed Art Museum. The event is free and open to the public.