Yes, yes he was.
I'm sitting here in my office with tears in my eyes from watching this. I hope to hell no one walks by. I tell you, in 1974, it simply didn't get any better, badder, cooler than that. Especially for a 14 year old white girl in Indianapolis.
It still gives me chills. He was a fucking genius. And, like many geniuses, he paid for it by turning into a fucking wacko. It's all very sad.
Go watch more Jackson 5 stuff on YouTube. You will be shocked and awed.