I realise this is a very old thread, but a useful one. I have many files with no tags, but in folders like Alkan - Chamber Music - Trio Alkan, Charles Valentin
I have just realised I can use the directory name via convert filename-tag %composer% - %dummy% - %artist%\%dummy%
and also convert tag-tag
ALBUM %_directory%
This allows me to use directory names efficiently and save LOADS of manual work.
I have a lot of files translated from APE where foobar2000 has reported minor errors at the end of each file, probably tags, but has omitted them completely from the mp3s. But that's another story.