If I were you, I would also copyright your edits, as you are not only protecting the song but the arrangement work you provide when you create edits
I copyright through France-Copyright (Berne convention on international copyright), by sending a zip file with all documents I wish to place under copyright. The zip file can be up to 128MB, well enough to place all edits of a same song in mp3 format and some extra files like lyrics, detailed content description, and scores etc… (be aware though that Photos and Films are not covered the Berne convention)