Here's Berry singing Almost Grown in front of a studio audience. He's simultaneously playing the guitar, singing, dancing, mugging, and making expressive gestures with his hands in order to entertain us.
What's striking about all this is how naturally it seems to come to him, and how effortless it appears.
But, I'm not sure of that, and it was apparent from some of his later videos that he could do all those things at the same time (though his singing in those later videos is usually off key.)
Here's a video of Berry performing Little Queenie, with a white backup band. His ability to multitask is highlighted here, since his bandmates are doing nothing but playing their instruments. That's by design, but it's also obvious none of the others could have done what he did.
What makes it really amazing is that he's the one who composed the music and wrote the lyrics as well.
(It's a little embarrassing the way these old-time videos would regularly cut back to the white audiences clapping along, as if to show other whites that it was okay to enjoy Berry's music.)
Finally, here's a video of Berry performing Oh Baby Doll. Same thing: playing the guitar, singing, and dancing, all while hamming it up.
It's sort of like watching a circus performer juggling three balls while simultaneously keeping a plate spinning in the air.
Except that at the same time, you know you're watching the guy who actually invented circuses.
Update, 4/19/17: I've just been informed by an anonymous commenter that Berry actually didn't compose the melodies, that another black musician named Johnny Johnson did. Oh well.