electroacoustic prose

The subject was not exactly changed by anyone, but it drifted off to something else. Lilly remembered that she had brought an electronic record for them to hear. They played it while they had coffee. Eric chuckled and made comments. The few words, said in German by a female voice, were interspersed by eerie, owl-like moaning and screeching. Clarence's thoughts drifted. He saw a garden of metal flowers, then a dark tunnel, an airless hell in which anything could happen, or spring out. It was an unknown world, yet completely known, as one knew one's own dreams, and yet did not know them -- because one could not completely interpret them, but not because one did not know them and their peculiar atmosphere.

Patricia Highsmith, A Dog's Ransom (1972)

I love depictions like this, made in passing, of the avant garde. The more marginal they are, the more unguarded and interesting they become. This one is quite finely nuanced; one character resists, but the central character responds -- and sympathetically, despite the hellish atmosphere evoked. The record's modernity is not an issue, though it is described in a vocabulary which is doubly atavistic: it speaks to Clarence's violent subconscious, and itself reanimates a fin-de-siecle lyricism: flowers of evil, seasons in hell. What was the original of this fictionalized record? Maybe some scholar of Highsmith and/or Stockhausen can tell me.