In this hour of Radiolab, stories of cross-species communication.

When we gaze into the eyes of a wild animal, or even a beloved pet, can we ever really know what they might be thinking? Is it naive to assume they're experiencing something close to human emotions? Or is it ridiculous to assume that they AREN'T feeling something like that? We get the story of a rescued whale that may have found a way to say thanks, ask whether dogs feel guilt, and wonder if a successful predator may have fallen in love with a photographer.

In tape five, three stories: first, a tale of how the cassette tape supercharged the self-help industry. Second, cassettes filled with history make an epic journey across Africa with a group of Lost Boys. And finally, Simon meets up with fellow Radiolabber David Gebel to dig through an old box of mixtapes and rediscover the unique power of these bygone love letters.

Mixtape was reported, produced, scored and sound designed by me, Simon Adler, with music throughout by me. Unending reporting and production assistance was provided by Eli Cohen.

Special Thanks to: Shad Helmstetter, Vic Conan, Glenna Salisbury, Jerry Rosen, Richard Petty, Sharon Arkin, Angela Impey, William Mulwill for sharing his cassettes with me, and to the British library for sharing some of their recordings from their South Sudan collection, which is housed at the British Library Sound Archive.

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In 1983, Simon Goodwin had a strange thought. Would it be possible to broadcast computer software over the radio? If so, could listeners record it off the air and onto a cassette tape? This experiment and dozens of others in the early 80s created a series of cassette fueled, analog internets. They copied and moved information like never before, upended power structures and created a poisonous social network that brought down a regime.

In tape four of Mixtape, we examine how these early internet came about, and how the societal and cultural impacts of these analog information networks can still be felt today.

Mixtape is reported, produced, scored and sound designed by Simon Adler with original music throughout by Simon. Top tier reporting and production assistance was provided by Eli Cohen.

Special thanks to: Alex Sayf Cummings, Martin Maly, Piotr Gawrysiak, Joe Tozer, James Gleick, Jason Rezaian, Gholam Khiabany and Mo Jazi. And to Arash Aziz for helping us every step of the way with our story about Khomeini. And Simon Goodwin for making us that secret code. And to Micah Loewinger to tipping me off to these software radio broadcasts.

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As the Vietnam war dragged on, the US military began desperately searching for any vulnerability in their North Vietnamese enemy. In 1964, they found it. It was an old Vietnamese folktale involving a ghost, eternal damnation and fear - a tailor made weaponizable myth. And so, armed with tape recorders and microphones, the military set out to win the war by bringing this ghost story to life.

Today, the story of these efforts and their ghosts that still haunt us today.

Mixtape is reported, produced, scored and sound designed by Simon Adler with original music throughout by Simon. Indispensable reporting and production assistance was provided by Eli Cohen.

This episode was produced by Annie McEwen, with original music by Annie. Original reporting was contributed by Trung Dung Vo and Nguyễn Vân Hà.

Special thanks to: Allison Boccia, Jared Tracy and Herb Friedman. And to Mathew Campbell for introducing me to the Wandering Soul tape to begin with. And to Erik Villard for all his help pulling those tapes and voices for us.

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In 1946 Bing Crosby was the king of media. He was the movie star, the pop star and his radio show was reaching a third of American living rooms each week. But then, it all started to fall apart. His ratings were plummeting and his fans were fleeing. Bing however, was not going down without a fight.

Today, the story of how Bing Crosby and some stolen Nazi technology won his audience back, changed media forever and accidentally broke reality along the way.

Mixtape is reported, produced, scored and sound designed by Simon Adler with original music throughout by Simon Adler. Invaluable reporting and production assistance was provided by Eli Cohen.

Special thanks to: Michele Hilmes, Pete Hammer, Rich Flores, Mara Mills, Jonathan Sterne, Claudia Mewes. Though their voices weren’t in the piece, input certainly was.

And to Mary Crosby and Robert Bader, for opening up Bing’s archive for us, and enabling us to fill this episode with so much of Bing’s music.

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Through the 1980s, the vast majority of people in China had never heard western music, save for John Denver, the Carpenters, and a few other artists included on the hand-picked list of songs sanctioned by the Communist Party. But in the late 90s, a mysterious man named Professor Ye made a discovery at a plastic recycling center in Heping.In episode 1 of Mixtape, we talk to Chinese historians, music critics, and the musicians who took the damaged plastic scraps of western music, changed the musical landscape of China, and reimagined rock and roll in ways we never could’ve imagined.

Mixtape is reported, produced, scored and sound designed by Simon Adler with original music throughout by Simon. Invaluable reporting and production assistance was provided by Eli Cohen. Additional reporting by Noriko Ishigaki, Rebecca Kanthor and our amazing anonymous Chinese reporter.

Special thanks to: Paul de Gay, Juliette Kristensen, Rebecca Tuhus-Dubrow, Nick Lyons, Michael Bull, Jiro Ishikawa, Hayley Zhao, Megan Smalley and Deanne Totto.

This episode would not have happened without each and every one of them.

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Ecologist Nick Haddad was sitting in his new office at North Carolina State University when the phone rang. On the other end of the line was... The U.S. Army. The Army folks told him, “Look, there’s this endangered butterfly on our base at Fort Bragg, and it’s the only place in the world that it exists. But it’s about to go extinct. And we need your help to save it.” Nick had never even heard of the butterfly. In fact, he barely knew much about butterflies in general. Nonetheless, he said yes to Uncle Sam. “How hard could it be?” he wondered. Turns out, pretty hard. He'd have to trick beavers, dodge bombs, and rethink the fundamental nature of life and death in order to rescue this butterfly before it disappeared forever.

**CORRECTION: An earlier version of this story incorrectly stated that the Army moved a beaver; in truth, they killed it. We also overstated the current tally of St Francis Satyrs off range; they are around 200, not 800. The audio has been adjusted to reflect these changes.**This episode was reported by Latif Nasser, and produced by Rachael Cusick. Original music by Jeremy Bloom. Mixing by Arianne Wack.

Special thanks to: Snooki Puli, Cita Escalano, Jeffrey Glassberg, Margot Williams, Mark Romyn, Elizabeth Long, Laura Verhegge, the Public Affairs and Endangered Species Branches at Fort Bragg.

Want to learn more? you can ...... read Nick Haddad’s book The Last Butterflies: A Scientist’s Quest to Save a Rare and Vanishing Creature... take a peek at Thomas Kral’s original 1989 paper about the Saint Francis Satyr... visit Fort Bragg's webpage about the Saint Francis Satyr

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One morning, Oliver Sipple went out for a walk. A couple hours later, to his own surprise, he saved the life of the President of the United States. But in the days that followed, Sipple’s split-second act of heroism turned into a rationale for making his personal life into political opportunity. What happens next makes us wonder what a moment, or a movement, or a whole society can demand of one person. And how much is too much?

Through newly unearthed archival tape, we hear Sipple himself grapple with some of the most vexing topics of his day and ours - privacy, identity, the freedom of the press - not to mention the bonds of family and friendship.

Reported by Latif Nasser and Tracie Hunte. Produced by Matt Kielty, Annie McEwen, Latif Nasser and Tracie Hunte.

Special thanks to Jerry Pritikin, Michael Yamashita, Stan Smith, Duffy Jennings; Ann Dolan, Megan Filly and Ginale Harris at the Superior Court of San Francisco; Leah Gracik, Karyn Hunt, Jesse Hamlin, The San Francisco Bay Area Television Archive, Mike Amico, Jennifer Vanasco and Joey Plaster.

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Episode originally published 09/21/2017