Well, I got a pretty quick reply from Latshaw, which I didn't expect. That's why I posted here.
Anyway, it's in the datamain.xml file. Sure enough, my lists are back!
Here's the reply he sent me.
Quote:
To copy the list of singers and their histories you need to copy the
datamain file and the entire singer history folder, which is located in the
Karma Data folder (which is located in your documents folder).
Whew! What a relief!
PS: thanks for your help!