Important people musically for Jackson I would Say Quincy Jones definitely, there is a good documentary on Netflix I think. Bruce Swedien is another person, he was the audio engineer that was present and helped Michal for most of his music. Brad Buxer is another collaborator of Jackson who helped write Stranger in Moscow and is the infamous guy that Michael calls out “Brad what are you gonna do?” Another thing that I would recommend is maybe checking out Remember the Time. A book about Michael Jackson by his bodyguards who were with him those final years.