A favorite lesson I taught (for 3rd graders) ages 8-9, was about the water cycle. I am not sure where I got the song from, but it works really well! It is to the tune of "Oh, My Darling." There is movement with the song. I hope this description is good enough to follow:
Condensation (push out with your hands), Evaporation (move your hands up towards the sky), Precipitation on my head (make it look like your hand is showering like a spout over their head), Accumulation (move hands infront of them in a swishing movement like the water in a river), The water cycle (move their hands in a circle), goes around again (turn around in a circle).