German composer Wilhelm Richard Wagner brought to audiences such operatic treasures as “Tristan and Isolde,” “Parsifal” and the “Ring” cycle. But his influence on music extended further than his mainstream popularity. He changed the way theater-goers saw opera, and his impact reverberates to the modern day. The North Carolina Opera is doing a performance of portions of his works. Host Frank Stasio talks with Timothy Myers, conductor for the opera’s upcoming performance; and Elizabeth Bishop, the lead actress.