Since I'm on the subject of Wagner's Ring cycle, [View all]

Does anyone one know of any cycle in which Siegmund and Siegfried were played by the same singer?

I can't imagine that there would be; Siegmund's tenor role is much more baritonal than Siegfried, who is a true heldentenor. And Siegfried needs to stay fresh for his debut, and not exhaust himself the night before singing Siegmund.

Still, I'm curious to know if this has ever happened...