Even professional musicians haven’t heard of him. But Russian violinist and composer Julius Conus did exist, and in 1896 he wrote a Violin Concerto in E minor. Years later, Jascha Heifetz recorded the piece, in which form it reached the ears of a Norwegian boy who would grow up to become the concertmaster of the Atlanta Symphony Orchestra. Now David Coucheron is excited to perform the Conus Violin Concerto for the first time himself March 7 and 9 with his colleagues in Atlanta. He spoke with GPB’s Sarah Zaslaw about this obscure but “surprisingly beautiful” work.