Knick-knacking Away

We are in the car on the way to school. The radio is off I realize Zack is humming in the backseat.

MMMmmmm he played two,
 mmmmmm mmmm, on my shoe, 
mmmmm mmmmmm

Zack? Do you know the words?

There are WORDS?

Yes.

I start singing them, he joins in.

This old man, he played two

he played knick-nack on my shoe

with a knick-knack paddy whack

give a dog a bone,

this old man came rolling home

This old man he played three

he played knick knack on a tree

Mom? What's it mean to play knick-knack? 

I shake my head. I'm just trying to steer the car here people. I wasn't ready for this.

Knick-knick is an onamonapia. Like bing bong bang.

He nods but he's not done.

So after knicking and knacking on things, he gives a dog a bone? 
Mom, this song sounds wrong. 
This doesn't sound like a kids song.
 I think there's something behind giving the dog a bone, Mom.


I sigh.

Please please let me keep a straight face for just three more turns until  we land at cardropoff.


He continues, and MOM? Why is the man rolling home? Is he drunk?  And if so how does he just keep on knick-knacking away? Shouldn't someone stop him?

I shrug and leave room for him to solve this big riddle on his own.