Okay, according to some Japanese articles, they oppose the making and distribution midi songs of a copyrighted song. To me, that's unnecessary, because it is possible to make derivative works even by making songs with your voice, and also can teach some people how music patterns work. Its like anti-fan music. A midi file is like a source code of a software, but without illegally hurting businesses (legitimate use). If that isn't enough, they wanted to collect copyright fees on schools too. Therefore rendering schools more expensive. It's already bad enough that textbooks with a passcode for online version REQUIRES you to pay money to register this key should you rent the textbook (therefore, violating the first sale doctrine).