The Cat in the Hat Knows a Lot About That! Season 1 Episode 4 - A Plan for Sand - Whale Music >Nick and Sally have made a song to sing to their moms, but they can’t get the ending quite right. The Cat in the Hat takes them to meet the best singing teacher in the world who is Humphrey, the humpback whale! While bobbing in the ocean, Humphrey teaches the kids that whales communicate by singing, and that it’s not how you sing that matters, but what you’re saying in the song. The kids return home to delight their mothers with their song!