2009 was a whirlwind year for Got Talent alum Susan Boyle. After captivating audiences with an instantly-viral performance of “I Dreamed a Dream” on Britain’s Got Talent, the singer found herself very, very famous. And Boyle’s celebrity only grew after a special ITV1 performance in December of that year, when she teamed up with world-renowned artist Elaine Paige to duet “I Know Him So Well” from the musical Chess. 

Susan Boyle appears on NBC News’ “Today” show. Photo: Peter Kramer/NBC

Paige is one of the two original vocalists who recorded “I Know Him So Well,” and Boyle’s tone and range fit right into the classic tune.

The best part of the performance is the look of pure joy on both their faces. If you don’t get chills listening to their flawless harmonies, you have no soul!

This duet was made even more special because during Boyle’s unforgettable appearance on Britain’s Got Talent, she mentioned how she wanted to have a singing career like Page’s. And just a few months later, the two talented ladies were sharing the stage.

In a 2010 interview with the Daily Mail, Paige confessed her admiration for how Boyle turned her viral moment into a full-fledged career.

“I am a huge supporter of Susan Boyle and admire what she has achieved,” the singer revealed.

Here’s what to know about “I Know Him So Well”

Released in 1984 as a lead single from the concept album Chess, written by ABBA members  Benny Andersson and Björn Ulvaeus and performed by Paige and Barbara Dickson, the success of “I Know Him So Well” helped transform Chess into an acclaimed musical of the same name.

Although the song failed to gain traction in the United States, it was a massive success overseas, reaching number one on Ireland’s and the United Kingdom’s singles charts.

“I Know Him So Well” is a popular song for contemporary artists to cover — Whitney Houston, Idina Menzel, and even the Spice Girls’ Mel C and Emma Bunton have put their own twist on this iconic track.

Now, music fans can add Susan Boyle’s unbelievable rendition to the list.