He broke free from R&B shackles, and moved into a pop style that bridged black and white music like no other artist before him. He was successful at bringing his own Motown into pop. After Michael Jackson, Pop become a colorless genre that evolved from the 50s and 60s white-dominated culture. At a quick glance, historic landmarks like the first black artist to earn more than the traditional 3 minutes on MTV display this achievement. But aesthetically, his music had all the ingredients to appeal to broader audiences which resulted in the first artist in music history to garner fans on equal amounts within the United States and across the world regardless of their skin color.
You'd have to be there to understand. But before Michael Jackson there was really no dancing act. There was really no military flak jacket dressing artists, or band-aid fingers, or bandaged arms. And there was very little of the bad boy attitude. Michael Jackson shaped all this for future generations. His dancing with elements of James Brown and Elvis Presley is still highly inspirational to even the young audience today, it completely shaped pop dance and helped shape future achievements like Break Dance, Disco, and modern R&B dance. It even helped shape rap moves. All this acknowledged by the artists themselves. Meanwhile his dressing act and his attitude completely defined what would become the 80's and 90's pop music and even touched Disco.
Music promotion underwent a total and complete revolution the day Thriller was released, three years after Off the Wall. Again, you would need to be there to understand. Thriller hit everyone on their heads like a thousand hammers screaming to the top of their lounges "WAKE UP!". It was a complete unexpected surprise. No one was really knowing what would hit them the next day when they went to bed. It wasn't just the musical, style. It wasn't just the fact this album forced critics to rewrite the rules about how many singles can come out of an album before it washes itself out. No. It was the music videos.
Thriller introduced into the music industry the concept of music videos as promotional tools with their highly aesthetic elements and completely revised production principles. I remember when I first saw the music video from Thriller. I was totally blown away. My jaw dropped. It's perhaps when I learned the real meaning of the word "Cool!". It blew everyone away. People even believed that there was a movie somewhere or the song was the soundtrack for a movie on the making. No one was ready for that... and the music industry? Man, you have no idea. It blew them off their socks. Since Thriller, everything changed.
Michael Jackson was also a producer. Suprisingly, even from tender age. He helped produce many of the Jackson's albums and produced most of his own solo work. No Michael Jackson Album or music video, was ever released that didn't have Michael Jackson work as a producer or writer.
Finally, Michael Jackson was the creative behind his own work. Nobody told him how to do it. He would tell others how he wanted it done on those things he couldn't put his own hand (like playing an instrument). Every song you hear is the work of Michael Jackson and Michael Jackson alone.
Please do not go that route. You are just absolutely wrong. The only thing you cannot see him doing is playing an instrument. But Michael could read musical notes and even defined the instrumentalization for his songs. This is someone that has been in constant daily professional contact with the music industry since he was 5!