Storyline Online: An online streaming video program featuring members of the Screen Actors Guild reading children's books. Each book includes accompanying activities and lesson ideas. Readers include Betty White, Melissa Gilbert, Elijah Wood, and more!
"Volcano Song" would be a good opening activity for the volcano lesson. It highlights the important aspects of volcanoes (such as lava and magma) in a way that the students will learn from and remember.
The Cat in the Hat Knows A Lot About That - The Rainbow Song. My younger students love this. They never forget ROYGBIV after learning this song. They like to sing it while waiting in line to change classes.