Near the end of « Un Amour de Swann » in Du côte de chez Swann is the evening at the house of Mme de Saint-Euverte, an extended virtuoso section of nonstop brilliance. This is just a tiny but fairly self-contained exceprt of four sentences, the first half of a paragraph (pp. 322-323 of volume 1 of the 1987 Pléiade edition; see also proust.page). I plan to expand it further later.
Swann had come forward, on the insistence of Mme de Saint-Euverte, and to listen to an aria from Orphée played by a flutist had placed himself in a corner where unfortunately he had as his sole perspective two middle-aged women, sitting one next to the other, the Marquise de Cambremer and the Vicomtesse de Franquetot, who, since they were cousins, passed their time at soirées, carrying their bags and followed by their daughters, searching for each other as if in a train station and not being content until they had marked, with their fan or their handkerchief, two neighboring places: Mme de Cambremer, since she had very few connections, being all the happier to have a companion; Mme de Franquetot, who on the contrary was very popular, finding something elegant, original, to show to all her beautiful acquaintances that she preferred to them an obscure lady with whom she had in common memories of youth. Full of melancholic irony, Swann regarded them listening to a piano interlude (Saint Frances parlant au oiseaux by Liszt) which had come after the flute aria, and following the vertiginous and virtuosic playing, Mme de Franquetot anxiously, her eyes distraught as if the keys over which he was running with agility had been a series of trapezes from which he could fall from a height of eighty meters, and not without casting at her neighbor looks of astonishment, of denial which signified: “That’s unbelievable, I never would have thought a man could do that”; Mme de Cambremer, as a woman who had received a strong musical education, beating the time with her head transformed into a metronome pendulum whose amplitude and speed of oscillations from one shoulder to the other had become such (with the kind of bewilderment and abandonment of the look that sufferers have who no longer know themselves nor seek to control themselves and say “I can’t help it!”) that at every moment she snagged her solitaires on the straps of her bodice and was obliged to straighten the black grapes she had in her hair, without ceasing to accelerate the movement. On the other side of Mme de Franquetot, but a little in front, was the Marquise de Gallardon, occupied with her favourite thought, the alliance she had with the Guermantes and from which she drew for society and for herself a great deal of glory with some shame, the most brilliant among them keeping her a little at a distance, perhaps because she was boring, or because she was spiteful, or because she was of an inferior branch, or perhaps for no reason at all. When she found herself nearby someone she did not know, as at that moment by Mme de Franquetot, she suffered that the awareness she had of her kinship with the Guermantes could not manifest itself outwardly in visible characters like those which, in the mosaics of Byzantine churches, placed one below the other, inscribe in a vertical column, next to a holy figure, the words which he is supposed to pronounce.