Boyle performed three songs as part of a special Mass to celebrate Pope Benedict XVI's visit to Scotland. Besides her signature hit "I Dreamed a Dream," she sang the hymns "How Great Thou Art" and "Make Me a Channel of Your Peace" for the crowd of 65,000 at Bellahouston Park in Glasgow.
"It's something I've always dreamed of, it's something I've always wanted to do, and here I am, finally getting the chance," Boyle told Sky News.
Boyle became an Internet phenomenon in 2009 when clips of her performances on Britain's Got Talent went viral on YouTube. She came in second on the TV show, then went on to sell more than 9 million copies of her debut album, also called I Dreamed a Dream. It was the top-selling album of 2009 worldwide.