I would say that this "program" sits in front of the PC.
Depending on the size of your collection, it is easiest, to compare files by sorting and filtering.
If you want to do it automatically, it is always tricky to find, which record is master.
It could well be that a track sinks in your esteem and you would have to reduce the number of stars.
This could only be achieved, if you also stored the date of the modification of that particular field as well.
Also, it could be you have similar songs that should get the same ranking but they are not spelled in the same way, e.g. as it is an extended version or something.
MP3tag has a good export language that lets you create lists so tha you can do that comparison in a database, if you like.