I have a text file with information that I would like to transfer to both the artist and composer fields. I know to use text file - tag, but is there a way to transfer the information to both fields at the same time?
According to the documentation, the choosen format string has to resemble the structure/content in your textfile.
But you can import your text file content first to ARTIST only and then in a second step use Convert Tag -> Tag and copy the content of ARTIST into COMPOSER.
Yes, if you have a copy of the data in your text file.