Charlotte Symphony Music Director Christopher Warren-Green is paying it forward. He credits singing in a church choir as a boy for sparking his interest in music. Now, as a professional conductor, he’s leading an orchestra with an ambitious mission: to become the region’s primary source for music education. Warren-Green has invited more than two dozen elementary through high school students from groups sponsored by the Symphony to join the Orchestra and Oratorio singers on stage at their performances November 16 and 17 at the Belk Theater.