Guys, that is a brillant song indeed and hats off to your choice. I don't usually comment on music because i don't know that much but u picked up on something that i find brillant as well - the guitar riff. One of the reasons why I think Michael Jackson was/is great is that he was very good at combining music genres.
According to what I know, in the 80s, rock music was becoming increasingly popular, with bands like Guns n Roses, Metallica, Megadeth and Bon Jovi leading the way to make rock more mainstream. These guitar riffs almost defined that commercial push, making guitarists like Slash and Malcolm Young almost as popular as the bands they belong to.
Michael Jackson capitalised on that trend while still staying true to the popularity of soul music of the time. The combination of rock guitar riffs in this song, together with the soulful voice of Stevie Wonder, breaks the trend for music to be associated with skin colour since at that time, rock was typically listened to by white people and soul by black people. As far as I know, the only other attempt at bringing white and black music together at that time was by Aerosmith and Run DMC in their song Walk This Way.
I think I am just rambling on here... just wanted to say - brillant song!