One hundred forty parishes are represented in the 500-member Papal Choir, including some from Delaware and New Jersey.
Catholic Diocese of Wilmington spokesman Bob Krebs said Archdiocese of Philadelphia leaders invited his members to try out.
"The fact that they opened it up to folks from neighboring dioceses was really quite nice of them to be able to include us, they didn't have to," Krebs said.
Hundreds tried out, and 28 parishioners from Delaware were chosen, including Michael Lundy and his wife, Patricia.
"It's something that we can share together," Patricia said. "It's such an honor to be a part of any part of that ceremony."
Make no mistake, the auditions were far from easy.
Michael Lundy is the music director at St. Mary of the Assumption in Hockessin. No stranger to auditions, even he said the 15-minute tryouts were tough. He said one ear-training exercise, in particular, where he was asked to repeat music played on the piano a capella was especially challenging.
"The passages he played were kind of long and then they started getting longer so you had to remember these notes and these tones of course that you had not heard before," he said.
The Lundys, along with the 498 other Papal Choir singers, have been rehearsing since July at the Cathedral Basilica of Sts. Peter and Paul in Philadelphia.
"It's a very deep and profound happiness and joy that you get from being able to serve the church in this way," Michael said.
The Papal Choir with sing during the big outdoor Mass on the Benjamin Franklin Parkway on Sunday, Sept. 27.
The World Meeting of Families runs through Sept. 25 at the Pennsylvania Convention Center in Philly.
Pope Francis arrives Saturday morning and stays through Sunday evening.