Talk:Hatsune Miku: Project DIVA Mega Mix/@comment-44371108-20200209213300/@comment-24947676-20200210005745

Sometimes people other than the producer have the rights to a song. For example, if a producer is signed on to a record label, SEGA can just get permission from the label. This is how the rights to samfree's songs can be renewed. Keep that word in mind. Licenses have an expiry date.

An example where SEGA wasn't able to renew the rights to to use a song is Kagamine Hachi-Hachi Flower Fight. The producer behind that song disappeared and wasn't signed on to any labels, and as a result, SEGA couldn't renew the license.

In the case of Unknown Mother-Goose (which has appeared in several other rhythm games *after* Wowaka's death, so...), it's most likely that the rights went to Wowaka's band Hitorie. I'm going to take a guess that either SEGA simply decided not to include Unknown Mother-Goose, or they asked Hitorie for permission to use the song and they declined.

Take this with a grain of salt though, I don't have a whole lot of knowledge about how licensing works.