Long before reunion tours became a natural part of being in a rock group, Simon & Garfunkel did what nobody thought they would do again: the duo reunited in September 1981 for a free concert in New York City's Central Park.

They'd long been celebrated for beautiful harmonies but Paul Simon and Art Garfunkel could barely stand the sight of each other by the time of 1970's Bridge Over Troubled Water, calling it quits the next year.

They subsequently recorded a few songs together, including Simon's "My Little Town" and a cover of Sam Cooke's "Wonderful World" with their friend James Taylor, but remained broken up.

When New York City asked them to reunite to raise funds to renovate the park, however, they decided to bury the hatchet and help their hometown. An estimated 500,000 people crammed into the park's Great Lawn for the event, which was filmed for HBO and recorded for a live album to raise funds.

Watch Simon & Garfunkel Perform in Central Park

Mayor Ed Koch introduced the pair from a stage designed to look like a New York City rooftop. They then launched into "Mrs. Robinson" and 19 other songs, which included a handful of Simon's solo hits and one new number from each.

Despite the years and acrimony, they sounded as if they had never broken up. But there was one glitch. The performance of Simon's new song "The Late Great Johnny Ace" was interrupted when a fan ran onstage after Simon sung a lyric about the killing of John Lennon, which had occurred nine months prior only a few blocks away from the site of the concert.

Concert in Central Park arrived on Feb. 16, 1982, and promptly became a double-platinum Top 10 Billboard smash. Bolstered by the success of the show, Simon and Garfunkel embarked on a world tour that, predictably, ended badly. They toured again in 2003 and 2004, and sang at the Rock & Roll Hall of Fame's 25th Anniversary concert. The duo then performed for what looked like the final time at a tribute dinner for director Mike Nichols in 2010.

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