Biography
"Trad", "traditional", etc., aren't artists' names;
See also Traditional. Tagging to an actual artist isn't always possible. However it is better to use "Traditional" as artist tag. If you are unable to do this yourself (eg, because Spotify tagged music with trad.), at least vote for "Traditional" on this page as the correct tag (Suggest a correction).
Biography text from Last.fm, available under CC BY-SA.