MP3 player software that supports custom tags?

Is there any freely available mp3 player (software) that can pick up all songs from the disk/library with a specific selected tag (e.g. 'kuthu padalgal', 'kamal hassan' , 'raj hates these' , 'nice interludes' could be some of the custom tags)?

There are a few that only work on ID3 tags (pre-defined list of tags like artist, year, genre).

Let me know if you have any recommendations.