MJ's history and blood on the dance floor album?

The Blood on the Dancefloor remix album was made because it appealed at the time to the younger generation with the dance style music. The HIStory album had his older music in there basically because that his history, clue in the title. He was trying to get the truth out in his songs and therefore used a more agressive tone which appealed to a lot of people because they were not used to his music being like that.