Entry from Earth by Daphne Castell (New Worlds #159, February 1966) gets off to a colourful start at a music festival on the alien planet of Pigauron. After this setup, the story cuts to Lord D’aon Auwinawo, a visiting cultural minister from Tren who is bored with the event and returns to his tents, only to be unexpectedly visited by Mirilith tak, an Assistant Secretary for the Festival, and Slok, a bulldog-like alien. The latter is the “Personal Complainant” to another of the attendees, and is there with a grievance about the noise D’aon’s slaves are making by singing during the night.
D’aon stays awake that evening to listen to them, and then orders them entered into the festival where they are received politely. After their performance, D’aon talks to one the slaves about their history, and this reveals a pattern of enslavement. The story (spoiler) subsequently ends with them singing “The Rivers of Babylon” revealing them to be Jewish slaves captured from Earth.
This has a colourful start, and an okay idea, but you can see the end coming from a mile off, even without the foreshadowing.
** (Average). 3,050