Yes, as Vicente points out below, this is heard by us as being one-to-1/2 tone higher than we hear recordings of today like Pavarotti, Kaufman or other artists. I do not think it is the result of the recording being sped up, because the pace is actually a bit slower than current orchestras play this in live Opera. There is a controversy that older orchestras tuned higher than we currently tune, and that may be the cause. Nonetheless, Kraus had a pure and clean voice that could really reach high notes cleanly and sustain beautifully without sounding like any kind of strain, especially up to the age of 45. He does a fabulous job of this aria and it sounds gorgeous even though marred by the movie sound track in which it is embedded. After listening to so many "dark" tenors these days (Kaufman, Villazon and others), I love the more briliant, higher, bel canto sound of Kraus.