Michael Jackson could not play the guitar part in 'Stranger In Moscow' and in 'Morphine', meaning that these credits that he gets on these 2 songs are apparently misleading.
This fact was also confirmed by the singer's nephew Taj Jackson:
"He wasn't very good at playing the instruments to the songs. He could tap on the keyboards and get around, just like anyone could, but he didn't know how to play the piano or a guitar" (Taj Jackson, 2020)
Besides, when Michael Jackson began his career with The Jackson 5, his brothers played all the instruments, so he focused on singing and dancing.