For these midwinter concerts, Andre de Ridder returns to Denver to show locals why he’s considered one of the most creative conductors in the world. The program begins with viola soloist Nadia Sirota taking on American Nico Muhly’s Viola Concerto, premiered in 2015 by Ms. Sirota and the Detroit Symphony Orchestra. Mark Stryker of the Detroit Free Press liked what he heard, writing, “The music is spare, tactile and a little spacey, and seems to briefly open a window on the infinite. . . . By the end, you feel as if you’ve been on a journey, happy to have been along for the ride.”