Uploading is mp3 files is fine.
$wgFileExtensions = array( 'mp3', 'jpg', 'png', 'gif', 'jpeg', 'pdf', 'txt' );
But moving is impossible.
File:Test 1.mp3 >> File:Test 2.mp3 = "The new file extension does not match its type".
Version: unspecified
Severity: normal