This performance of Tristan und Isolde might go down as one of the greatest I have ever heard. Kirsten Flagstad is at her absolute prime, and unlike many of the broadcasts that exist of her Isolde from the 1930s, this one gives you a visceral sense of how gigantic her voice was. And yet the size of her instrument seems almost secondary when you consider the level of artistry and feeling she brings to the role. Set Svanholm's honey-toned Tristan is well-paired with Flagstad; matching her in sensitivity if not necessarily in sheer volume. Still he brings a high degree of intensity to his Act III monologues, riding over the orchestra with remarkable ease. Hans Hotter is superb as Kurwenal, Ludwig Weber delivers a stoic, yet heartfelt portrayal of King Marke and Viorica Ursuleac makes a compelling argument for why Brangäne's high-lying tessitura is better suited for a soprano. Even in the midst of all this vocal greatness, perhaps the true star is Erich Kleiber who finds deep meaning in almost every single bar of music.