They could of just.... asked Michael Jackson Estate's lawyers and Brad Bruxer.
Which one?
The lawyers or Brad?
Each of them claimed that the work right is belong to them.
SEGA is confused on who to give the royalty to.
Unlike Sonic 1 & 2 that's clear that the music right is belong to Dream Come True.
What I heard is Michael created the music with humming and singing, Brad does all the work to materialize them with the music instruments.
But then again, it was never documented.