I have two kids that are 4 and 2, and call me a bad parent, but they love rocking out with me when we are in the car. Right now their favorite song is "Blood" by In This Moment. It was real cool when they were singing it to my 80-year-old grandma who couldn't understand why they would be singing a song about blood. My point... Rocker kids are the best, and I found a video of a couple three-year-olds that warmed my heart! 

Personally I think the best part comes around the :56 marker. Once you get there, keep your eye on  the smaller of the two kids, he’s got the rock/metal front-man thing down to a science.