By Greg Argos

PHILADELPHIA (CBS) — An elite group of choir members from Archmere Academy are practicing for a special international performance.

A final rehearsal is underway for 29 students in Claymont, Delaware.

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The choir heading to Rome on Sunday and next Wednesday,  Pope Francis himself will listen to the music.

“Nerves are a good thing to a degree but I tell them to stay focused on me–not to worry about what’s going on around you. Worry about what I’m doing and concentrate on me and what we’ve done in rehearsal,” said choir director David Ifkovits.

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“Being able to encounter the most influential man on the planet in terms of faith and Catholicism just stuns me a little bit every time I think about it,” said Pat Beck, a senior at the school.

This tight-knit group also stunned late last year in October when fellow Mastersinger Anthony Penna died in a car crash.

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He was supposed to be the 30th member to make the trip.

“The loss of Anthony was so sudden and devastating for all of us,” said Beck.

A piece of work commissioned by the group performed for the first time Wednesday Anthony’s mother and sister in the audience.

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“It will live on as long as the piece is published with his name on it saying it’s in his honor,” said Ifkovits.

“Without him, it’s been different, but we’ve grown and we’ve shared in the tragedy,” student Danielle Cuoco said.

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Now the Mastersingers plan to honor Anthony, push past their nerves, and prepare for perhaps the biggest performance they’ll every experience.