Set aside Wednesday evening for a magnificent concert at the Freemason Hall. It opens with music by Clara and Robert Schumann, including songs and the viola work Märchenbilder. After the interval comes Petrichor, where festival composer Kristine Tjøgersen evokes the scent of rain through sound. The Trondheim Soloists and the Absalon String Quartet conclude with Elgar’s Introduction and Allegro.