At 70, Matti Salminen is making his final appearance at the Deutsche Oper Berlin, the Finnish bass’ longtime Stammhaus this coming Saturday. There are still plenty of tickets available for what promises to be an exciting performance of Tristan und Isolde. Graham Vick’s 2011 production ain’t much to look at, but the evening’s cast is hard to top. Nina Stemme, today’s most sought-after Isolde, will appear alongside Stephen Gould, who set a new bar for Tristan at last summer’s Bayreuth Festival. Salminen sings the weary Marke, and if his appearances here in recent seasons as Gurnemanz and Hagen are any indication, there’s no need to worry about the septuagenarian disappointing. Donald Runnicles, fresh off of Friday’s premiere of Die Entfühung aus dem Serail, will conduct.