I just thought of this, but why not have a cloud based score tracker?
The concept:
Users can associate an account with their game. By doing so, their progress and score is accessible from all devices, PC, iOS, or Android.
In practice:
The account creation can be handled in anyway, but a few ideas could be to tie it to the forum's login, use Google's authenication, or Facebook's authentication.
I'm not sure how metadata such as progress and score are currently stored, but we can generate a hash value with the file as a key, and associate the metadata with the hash value. This information then can be stored on the cloud account. By doing it this way, there is no need to upload large MIDI files onto the server, and avoids duplicate songs being uploaded by multiple people.