"How are you still sitting here?" asked CBS News correspondent Steve Hartman.
"I guess they don't need a harmonica player in heaven yet," Mackie said.
Have an idea for Assignment America? Send us an email.
Mackie, a Scottish-born retired horse trainer, lives in a camper in Northwest Washington State, even though technically, medically, he should have died a long time ago.
After his ninth heart surgery, Mackie's doctors had him on 15 different medicines. But the side effects made his life miserable. So one day he quit taking all 15 and decided to spend his final days doing something he always wanted to do. He used the money he would have spent on prescriptions to give away 300 harmonicas, with lessons. When he didn't die the next month, he bought a few hundred more.
"I just started going from school to school," Mackie said.
It is now 11 years and 16,000 harmonicas later.
To keep the kids interested in music as they get older, Mackie now spends the bulk of his social security check making what he calls "strumsticks." He's given away thousands of these, too. He also buys store made instruments for the kids that show special interest and provides free lessons to everyone by getting the older kids to teach the younger ones.
"I tell them music is a gift," Mackie said. "You give it away - you give it away and you get to keep it forever."
The end result is something truly unique to this corner of America. It seems everywhere you look, everyplace you go, every kid you meet has the same genuine passion for fiddle music.
"I can't explain the joy," Mackie said. "I don't think Bill Gates feels any richer inside than I do."
"Do you think you're still living today because of the kids and the music?" Hartman asked.
"I really believe that," Mackie said.
After that story first aired, one of our viewers gave Mackie a $5,000 donation. Mackie used the money to hire a part-time teacher who is now showing the kids how to make the strumsticks. The hope is they'll carry on the mission after Mackie is gone - if Mackie is ever gone. Since we met him, he's had several more heart attacks, and just last week had his tenth successful heart surgery.