'La Maîtresse du piano' involves the young Czech Mathias, who has come to Paris to paint but ends up as a photographer. He meets the young René at art classes, and he befriends him and introduces him to his mother the piano teacher, Mme Bertin. When asked, Mathias tells René he's a virgin, whereas René startles him by saying that his mother likes him to keep her widowed friends happy, that at present he's satisfying three of them, and even that his mother fancies Mathias. Mathias says he prefers younger fare. And then they visit a widowed cousin who's deaf, ugly, walks with a stick and René reveals he lost his virginity to. Then a young couple arrive and walk around naked, and Mathias later hears them having sex with Mme Bertin. Later, he even hears René having sex with his mother.
But the story isn't really about incest or gerontophilia, it's more about moral corruption, and Mme Bertin's jealousy and greed is extremely destructive. Mme Bertin has hoped that René will marry Hélène, who's from a weathy family, but Mathias falls in love with Hélène, the feeling is reciprocated, and it's time for Mme Bertin to wreak revenge. And she does so on a huge scale, causing two suicides, one premature death, and obvious misery for the survivors.
'Le Baron de Gloeden' is also about an artist who turns photographer: in 1926, the seventy-year-old German Gloeden speaks of his past over the previous fifty years. He mentions that he visited Capri – where the gay writer Jacques d'Adelswärd-Fersen was exiled and about whom Peyrefitte later (in 1959) published L'Exilé de Capri – but decided that Sicily was a far more beautiful place, so settled there. It's not long before he takes up photography as a way of earning money, and continues this occupation for many years. He's particularly interested in the naked young boys around Taormina, and of course takes many photographs of them. He writes about the many customers who have come to him, including generations of the same family, and he keeps a visitors' book for them to sign. The police come to visit him as they're dubious about his photographic activities, but they can't find any wrong-doing, and none is mentioned.
The note at the end of the story made me wonder if Gloeden had in fact been a real person, and he certainly was. Peyrefitte has based it on the biography of the photographer Baron Wilhelm von Gloeden (1856–1931), who is noted for his (non-pornographic) studies of naked boys.
Baron Wilhelm von Gloeden