In Hari Kunzru's novel White Tears, two young white men, Carter and Seth, create music reusing old jazz and blues songs. Carter has a lot of recordings that he created by walking through the city wearing a set a headphones into which he had built a powerful microphone. Seth has a big collection of old jazz and blues records, many of which are rare.
One day, Seth and Carter combine a street recording of someone singing a song with a street recording of some guitar playing that seems to fit the song very well. They post the resulting recording on several websites, pretending it was made by a certain Charlie Shaw, a name they made up. One of the persons who respond to the song is a record collector using the pseudonym JumpJim, who thinks that the music is a 1928 recording by Charlie Shaw that he thought had been lost. In other words, the name that Seth thought was fictitious is the name of a real blues singer who supposedly recorded that song. What follows is a nightmarish descent into America's racist and segregationist past.
But the question is, what is the meaning of the record collector's pseudonym, JumpJim?