I think you just can’t go wrong with Dr. Seuss. The Sleep Book is one of my favorites.
In this book, we get to see the story of all these fantastic creatures getting ready for bed. Each page or two is devoted to one story of bedtime prep somewhere in this Seussian realm. Every so often, we get a total of how many creatures are sleeping and at the end, we see what this number will be once the listener goes to sleep.
As always, the rhyming rhythm of this book is just perfect. The illustrations are so much fun with engagingly outrageous creatures and a lot of nighttime/twilight color schemes. This classic is a little overlooked I think because of its length. However, with the format it uses, you can easily omit several pages here and there and not lose the train of the story. Then when your listeners are able to sit for a longer book, you can read it cover to cover. I bet it will become a favorite!