Hillside Lullaby by Hope Vestergaard is not explicitly musical in nature, but it has a rhyming scheme and rhythm that could turn into a beat the children you are reading it to can stomp/clap/snap. The illustrations are very cute and so is the story. It just talks about different animal moms telling their children to sleep, as well as the songs/lullabies each animal hears as it is chased off to bed. This book would be a good fit for pre-k to early elementary general music. You could always write a melody to go along with the words if you want, it is already very lyrical. You could also have the kids split into sections and assign them a sound they make at certain points in the story in order to get the kids more engaged.