Feature Request: Support Multiple Artists for a Track

[libregeek]

It would be great if SMP can support multiple artists for a track as we have in Quod Libet (https://quodlibet.readthedocs.io). This would be helpful for people like me who stores atomic values in a tag.

For example, if a track is performed by Artist X and Artist Y then I would store artist="Artist X" and artist="Artist Y". This would help me in two ways - I can search the song easily based on one artist and easily use the auto-suggest feature in the tag editor (Ex Falso).