Talk about singing for your supper. Many a soprano headlining a symphonic gala would reckon she had earned her fee performing either Richard Strauss’s transcendent Four Last Songs or the Final Scene of his Salome, in which the heroine makes morbid love to John the Baptist’s severed head. Well, not only is the admired Gun-Brit Barkin singing both those showstoppers, she’s also throwing in big arias from Fidelio (Beethoven) and Tannhäuser (Wagner). —M.G.