Pop music surrounds us, but how often do we really listen to what we’re hearing? Switched on Pop is the podcast that pulls back the curtain on pop music. Each episode, join musicologist Nate Sloan and songwriter Charlie Harding as they reveal the secret formulas that make pop songs so infectious. By figuring out how pop hits work their magic, you’ll fall in love with songs you didn’t even know you liked.

Listen closely to the start of the 2015 hit "Hey Mama" by David Guetta, Nicki Minaj, Afrojack and Bebe Rexha and you'll hear voices intoning a chant: "Be my woman, girl, I'll be your man".

It's sample from a 1948 recording called "Rosie", and it's the propulsive hook of "Hey Mama", driving the song to over a billion views on YouTube. The voices in the sample belong to CB Cook and ten other unidentified prisoners at the Mississippi State Penitentiary, aka Parchman Farm. These men never got credit for their work, even though it's been reused by everyone from Guetta to the Animals to Nina Simone.

This week, Nate and Charlie investigate the story of "Rosie" to understand an inequity that lies at the heart of the music business and the national consciousness.

[audio audio="https://traffic.megaphone.fm/VMP7564895116.mp3" title="Investigating a Crime at the Heart of the Music Industry" descr=""]