I wonder if he was better in the Wagner repertory than in the French repertory. For some reason, I see many of his performances by Wagner but few of his French opera performances.
About Flagstad, I think that she was a real diva. She didn't like performing with Melchior too. The reason why Martinelli partnered her in Tristan at Chicago was because she was hoping to find a substitute for Melchior. I don't know if this is real but it's what I heard. Piso, I wonder why you don't like his Otello. I found his Otello more aristocratic than several other top Otellos, but I guess each singer shaped Otello in a different way so...
John, if you're interested, the closest thing to that TV soap opera about real opera is El Duo de La Africana. It's a zarzuela about a performance of L'Africana. If you're curious for an example: here's 1 from my collection: