That is some seriously wicked multitracking overdub.
Giving the audio geek in me a second of blog time:
Described as a movement to inspire and connect the world through music, Playing For Change was created in 2002 when founders Mark Johnson and Whitney Kroenke began recording local street artists. Mark then had the idea to layer the separate tracks over each other to connect artists from all over the country. The result was an award-winning documentary, “A Cinematic Discovery of Street Musicians.”
For those audio hipsters that bemoan the death of analog and vinyl, this is what audio is all about: Good music by good players brought to people. And yes, having musicians in different parts of the world overdubbing a track was possible back then, but only if you had lots of money to be sending a messenger around the world with the master multitrack tape and praying to every deity that it wouldn’t get damaged.
Plenty of more songs in the link. Enjoy.