The man primarily responsible for the bass guitar, played as you know it today.
But he didn't just change how the bass was played, he even changed what music sounds like entirely.
In modern recordings, the bass is usually the loudest instrument in the mix. Music didn't always sound this way. This is the guy that changed that.
Most musical historians say that this song probably marks that turning point.
Here is some cat's transcription of this recording, which puts the bass even more front and center:
http://www.youtube.com/watch?v=-dXnJV8-l8c
insane
He's a little stiff, because it's literally him reading his own written transcription, but that only serves to make it all the more clear and obvious the complexity of JJ's licks. My god, what a motherfucker!
This cat nailed (albeit a tad stiffly) almost every single rhythmic nuance.
Ridiculous.
Edit: Oh, and one more detail. Unlike this kid, who played everything quite admirably, JJ only used one finger on his right hand (!) People referred to it as "the hook".