My favorite is "Each of us is a Flower, Growing in Life's Garden." However it's a bit hard to understand with all 19 voices singing at the same time. I'll have to capture Tom and Abby singing it at home for me so you can hear the lyrics better.
Water Travels in a Cycle
I Live in California
Each of Us is a Flower, Growing in Life's Garden!
The World is a Rainbow
Start Spreading the News, 1st Grade, 1st Grade!