The dozens. It's a name for a style of joking that was born in urban neighborhoods and focuses on insults or put-downs. It’s a style of humor that many music scholars say has paved the way for modern rap.

Elijah Wald has studied this type of humor for a book called "The Dozens: A History of Rap's Mama."

At its core, 'the dozens' is a verbal joust of yo' mama jokes and other taunts, But it's grown to a form of social interaction that dates back to African ceremonial rituals, and "provided a wellspring of rhymes, attitude, and raw humor that has influenced pop musicians from Jelly Roll Morton to Ice Cube."

Read an excerpt from "The Dozens"

Guest:

Elijah Wald, author of "The Dozens: A History of Rap's Mama"