Polish composer Karol Szymanowski’s Król Roger (King Roger) is by any measure an operatic rarity. Written between 1918 and 1924, and enjoying a handful of outings until 1949, it was entirely neglected for the following twenty-six years. It has experienced something of a renaissance since 1975, when conductor Charles Mackerras led a performance with the New Opera Company in London, but Kasper Holten’s production still marks the first time that it has ever had an outing at...