No. The Planet of the Apes opera is definitely The Ring of the Nibelungen. Lets say:
The gods, Wotan, Fricka, Brühnhilde are gorillas.
Hunding and his crowd are orangutans.
The Rhine Maidens and Erda are chimpanzees.
The Nibelungen are small tree monkeys.
So the three chimpanzees are swimming in the Rhine and a small tree monkey climbs down and steals their gold.
And the Volsung are human. Siegmund and Sieglinde are the first humans. When Wotan takes away Brühnhilde's godhood she turns into a human.
This is a great concept because suddenly the whole opera cycle makes sense. Of course it's now too revolting to watch. If we truly understood it, we couldn't watch it. Because the Ring is about race and the superiority of one race over another.