Sony's Walkman forever changed the way we listen to music, making it for the first time portable. After 31 years, the company has announced they will discontinue the Walkman in Japan, effectively making them no longer available for purchase in the United States.

Americans have long moved on from the Walkman, listening to music on devices like the Discman, then simple MP3 players until the iPod came around in 2001. And in the nine years since the iPod, Apple has sold more than 100 million of those devices while in it's more than 30 years, Sony sold around 200 million Walkmans.

Celeste Headlee sits down for an after-air conversation about the first mass-market rap single, "Rapper's Delight," which was released by The Sugarhill Gang 30 years ago this week. She's joined by hip hop musician Paul Miller (better known as DJ Spooky) and Keith Shocklee, who produced Public Enemy with The Bomb Squad.

The Sugar Hill Gang's "Rapper's Delight" hit the disco and pop charts 30 years ago this week, transforming hip-hop from live street perfomance to a mainstream moneymaker. We look at the impact of 30 years of "Rapper's Delight" on music and culture with Mark Anthony Neal, professor of black pop culture at Duke University, and Paul Miller (better known as DJ Spooky). And for a firsthand account of the phenomenon that was the Sugar Hill Gang, we talk to Keith Shocklee of The Bomb Squad, and a producer for Public Enemy.

(Celeste continued the conversation with Miller and Shocklee in an After-Air conversation: Check it out below.)