When Hervé Tullet’s Press Here burst onto the scene in 2011, it became an instant must-have for every collection, proving that you don’t need a digital device—or even flaps, pop-ups, or fuzzy pages—to have a whole lot of interactive fun. His follow-up, Mix It Up, was equally successful, this time using clever instructions to immerse kids in color theory, seemingly allowing them to create new colors by dabbing blobs, shaking the book, and SMOOOOSHing the book’s pages together (ok, so the smooshing sound is just what we yell when we do it at home).

And now we have Say Zoop! It clearly follows in the steps of the others, yet also takes the format to a new level. The previous two books help kids enter into a planned experience through playful, yet carefully plotted prompts. But while those books trick kids into thinking they’re in charge, Say Zoop! actually puts readers at the helm, helping them create something that’s wholly their own along the way. The book’s basic rules are deceptively straightforward. If you see a blue dot, say oh. If you see a red one, say ah. For a yellow dot, say wahoo! But there’s nohting simplistic about it.

Watching two-year-olds concentrate on making the right sounds in the right order on a spread filled with different dots allows you to really watch their little wheels as they turn. Using colored dots to playfully evoke and manipulate vocalization, this clever book also represents an ingenious introduction to the concept of reading music. When the dots go up, raise your pitch. When they fall, drop it. What does that melody sound like when you sing it? What about when I do? As the pages encourage kids to play with vocal spacing, volume, pitch, and even emotion, the reading experience morphs into exploration. What do those prompts sound like if you’re shivering, or crying, or fighting? What about if they’re coming from a car or a bird? What about if they’re layered one on top of the other or if they swirl into zigs and zags and blobs and splats?

And what if the dots turn orange, purple, and green? In my house, the answers are: beep for orange, high pitched chicken noise for purple, and endless debate for green. (No NOT plork, no NOT gebeegebeegebee, no NOT bamboozle, no NOT tuna salad, no NOT snoo.)

Hours after one of our booksellers, Merrilee, read Say Zoop! for storytime earlier this week, a father came back in to grab a copy, saying he just couldn’t get the book out of his mind. And you know, neither can I. Especially since Hervé Tullet slyly, maddeningly, ends his stories with invitations to start over or continue the adventure, there really is no end. How long does it take you to zoop it up? Ten minutes? An hour? Well, that’s entirely up to you.