Here is a sample of the song for you. It focuses on SUPPLY and DEMAND as well as SCARCITY. I sing it along with the instrumental version of the Green Day song "Good Riddance" but you can sing it or rap it to anything you want.
The Water Song
Water, water everywhere, but not a drop to drink.
Water, water every where and in the kitchen sink.
There’s water everywhere, but still there’s scarcity.
Water, water everywhere, now listen and think.
Water is inside of me and it makes up my mind.
I drink some water when I want to unwind.
The Spanish call it agua and a Chemist H2O.
If you put in on a plant, then the plant will grow.