Some MP3 audio files are not recognized by Nautilus and xdg-mime, unless they have .mp3 extension. 37 sample files can be found at https://bugs.launchpad.net/ubuntu/+source/shared-mime-info/+bug/492363/+attachment/3146483/+files/unrecognized_mp3s.tar (130Mb total)
Some MP3 audio files are not recognized by Nautilus and xdg-mime, unless they have .mp3 extension. 37 sample files can be found at https:/ /bugs.launchpad .net/ubuntu/ +source/ shared- mime-info/ +bug/492363/ +attachment/ 3146483/ +files/ unrecognized_ mp3s.tar (130Mb total)