When the Nashville Symphony opens its new $120 million concert hall this fall, the celebration will be clearly designed to draw in more than just your average fan of Beethoven and Brahms. In country music’s undisputed capital city, outreach is a must for a classical orchestra, and Nashville’s opening concert at the new Schermerhorn Symphony Center will feature, among other guests, jazz/bluegrass banjo legend Bela Fleck and crossover bassist extraordinaire Edgar Meyer. Conductor Leonard Slatkin will lead the gala, as the orchestra is between music directors following the death of longtime leader Kenneth Schermerhorn last year.