Leonard Slatkin leads the Detroit Symphony Orchestra at the Spring for Music festival at Carnegie Hall. Torsten Kjellstrand/for NPR hide caption

itoggle caption Torsten Kjellstrand/for NPR

In Kurt Weill's opera, the city of Mahagonny was founded by three fugitives hoping to extort money from prospectors. Javier del Real/Teatro Real hide caption

itoggle caption Javier del Real/Teatro Real