For the centenary of Finland’s Independence, the Savonlinna Opera Festival brought back Kari Heiskanen’s spectacular 1992 production of Aulis Salinen’s Kullervo. The excellent Finnish soloists and glorious choir unflinchingly offered this opera of vocal blood and guts. Conductor Hannu Lintu fired up the Savonlinna Opera Festival Orchestra in Sallinen’s thrilling music.