Brad Sundberg who does the "In The Studio with Michael Jackson" Seminars talked also about Keep The Faith.
I read in an article:
Michael loved “Keep The Faith” and always intended to include it in the new album. Michael and the team worked very hard, long hours on preparing the track, the music, everything. However, when belting out the final vocal, something happened that threw the entire song out of whack; Michael’s voice cracked
Michael was really taken aback and got upset about it. Because his voice was cracking, the pitch of the song would need to be dropped in order for Michael to deliver the vocals the way he wanted to.
Everyone was supportive, and they started over.
The final version that we all know and love from the “Dangerous” album, Brad recalled, is Michael delivering the track as if to say “I’m sorry” and “Thank you.” He said you can hear it in his voice.
I personally love Keep The Faith. And I would like to know how much of a difference this probably was. Always thought he sounded deeper because he got older.