Have a look at this post: Importing metadata and tagging the files comprising an album
If you add the artist as a "column" in the text file like:
I sing for you.mp3;Abraham
At night I howl.mp3;Bebraham
The waters edge.mp3;Cebraham
In the middle of the night.mp3;debraham
For the import you define the fields
%filename_ext%;%artist%
and the correct artist should end up in the correct file.