Sorry if this has been suggested before. I think it would be cool if the database can keep track of which file has been played so that the new/unseen ones can be highlighted on the renderer (similar to an email client where new/unread emails are highlighted). The highlight can be shown as a different icon, or simply put the word "new" in front of the file name.
I think this is useful if you have lots of files inside a folder. It might take several days to go through the whole folder and it is easy to forget which file were played last.