She didn't know him, and he didn't know her: Seeger was already approaching legendary status, while she hadn't recorded a single tune. Yet, Harris was inspired by his integrity, and she'd learned to play the guitar by listening to his classic "Where Have All the Flowers Gone."
"I actually wrote him a letter, hand-printed, front and back, I don't know how many pages, saying I want to sing folk music, but I don't think I've suffered enough," she said, laughing. "He actually wrote me back ... basically saying life will catch up to me, and encouraged me to be bound for glory. Just hearing from him was one of the most amazing things that had ever happened to me, up to that point."
On Sunday, Harris will perform at Madison Square Garden in a tribute concert to Seeger on his 90th birthday. The event will also feature Bruce Springsteen, Dave Matthews, Eddie Vedder, John Mellencamp, Arlo Guthrie, Joan Baez and dozens of others.
The concert will surely be an homage to one of music's most revered voices, a man known for his poignant protest songs and social activism, from the fight for racial equality to labor rights and world peace.
He has been a fervent anti-war activist and is credited for popularizing the civil rights anthem "We Shall Overcome." His leftist politics (he was once a member of the Communist party, which he later renounced) got him blacklisted during the 1950s.
While his politics sometimes overshadowed his music, the Rock and Roll Hall of Fame member is considered one of folk music's greatest artists, and inspired artists ranging from Bob Dylan to Bruce Springsteen, who in 2006 released the album "We Shall Overcome: The Seeger Sessions," which features the Boss singing Seeger's songs.
But Seeger is not interested in celebrating past achievements at Sunday's event. He says he only agreed to take part in the event because it will benefit the Hudson River Sloop Clearwater, a nonprofit organization he founded more than four decades ago to help preserve the river, which has suffered from pollution.
Funds from the concert will help restore the Clearwater, the huge boat Seeger built to draw people's attention to the organization. (Tickets ranged from $19.19, the year he was born, to $250, with the majority of seats at $90 to honor his birthday.)
"We need to raise an endowment fund" for the boat, said Seeger, who lives along the Hudson River in Beacon, in upstate New York. "I agreed to the concert, although I don't like big things."
Harris said putting the focus of the concert on the Clearwater is another example of Seeger's principles being paramount to his music.
"It's never been about Pete," said Harris, who will perform two of his songs. "It's always been about the world and what he believes in and doing the right thing and making the world a better place. He's really lived what he believes; I think it's an inspiring example for all generations."
Seeger will perform one song - but he's not saying which one. "No one knows except me. It's a secret," he said. (His many iconic songs include "If I Had a Hammer" and "Turn! Turn! Turn!")
Seeger, whose many honors include a Presidential Medal of the Arts, is typically humble when asked which song he'd most like to hear during the anticipated four-hour concert.
"They don't need to sing my songs, there are a lot of good songs," he said.
Seeger recently released a new album, "At 89," his first in five years. He played during the inauguration festivities for President Barack Obama in January and performed at the New Orleans Jazz and Heritage Festival in April.
But he prefers to sing and strum his signature banjo for children: "For the rest of my life I hope to sing only for the children ... and I like to sing with the kids in the school. Kids are the hope of the future."
By Nekesa Mumbi Moody