Beans, Beans, the Musical Fruit
"Beans, Beans, The Musical Fruit" (alternatively "Beans, Beans, good for your heart") is a playground saying and children's song about how beans cause flatulence (farting). The basis of the song (and flatulence humor in general) is the high amount of oligosaccharide present in beans.
Source: Wikipedia — Beans, Beans, the Musical Fruit (CC BY-SA 4.0)