Excellent answer. :clapping:i think the proper answer is no one really knows, because even though he may be credited with instrumentation on the albums, he's not shown us any sign as to the extent of his performance skills.
as far as credits go, on Off The Wall, Thriller and Bad he's credited for playing percussion.
on Dangerous a lot of the stuff was synthesised or programmed on various machines so it was mainly keyboard work and i think i remember him being credited for that somewhere but not much else.
then on HIStory it expands in getting into keyboard, synths and guitar. he's credited with virtually every instrument on Morphine. and also drum programming (though i'm 90% sure that just means laying down his beatboxing).
and on Invincible it's the same scenario as Dangerous where a lot of the tracks had mainly synthesis and programming so credits read like "All musical instruments performed by Michael Jackson and Rodney Jerkins".
i think many people overestimate the fact that you can simply play an instrument without taking into account how skilled/naturally talented you are at doing it. same with thinking that if their artist plays but doesn't (can't) read music then they're somehow extra special, lol. (wrong)
Lauryn Hill picked up and learned the guitar in a matter of a few months, then went and made a full album from it with just three chords played differently on all 12 tracks
sounded good, mind you.