The Mater Dei High School Chamber Singers rehearse a song they will perform for the Pope in Italy, and during high mass in St. Peter's Basilica in Vatican City in Rome. About 130 students in Mater Dei High School’s choir, who are scheduled to perform at a Papal audience and sing high Mass in St. Peter’s Basilica. They’ll perform sacred music in the Sistine Chapel, including Sicut Cervus by Giovanni de la Palestrina, which was written for that venue, said Scott Melvin, the school’s choir director. They’ll also sing African-American spirituals. On Wednesday, a group rehearsed Hosanna in Excelsis by Brent Pierce, a complex piece with as many as nine different singing parts. Melvin urged them to “Smile and have fun. Make it beautiful.” And it was. The students and about 100 parents will arrive in Rome Friday, then immediately board a bus for Maiori, about three hours away. From there, they’ll take day trips to Pompeii, where they’ll tour the ancient ruins, and the island of Capri. They’ll sing with a choir from a Maiori high school and be officially welcomed by town officials. Then it’s back to Rome for the main events. On Wednesday, they’ll attend an audience with Pope Benedict XVI, arriving in St. Peter’s Square at 7:30 a.m., or three hours before the audience is scheduled to begin. By 10:30 a.m., when the Pope is to appear, they hope to be on stage with him (“It’s been optimistically assured to us” by Bishop Tod Brown’s office, Melvin said). However, Melvin has been trying to keep expectations subdued, telling students it’s possible the Pope might not even be there. That hasn’t stopped Mater Dei senior Nicole Bundy, 18, of Costa Mesa, from getting her hopes up. “I’m a Catholic. Wow, this is the man who leads our entire religion. It’s an amazing idea that we get to go and be near this man,” she said. On April 2, the choir will sing a 5 p.m. high Mass at St. Peter’s Basilica. Later that evening, they’ll tour the Vatican museums and the Sistine Chapel, then give a private recital for parents in the Sistine Chapel. That’s one of the highlights that senior Keith Morton, 18, of Costa Mesa, is anticipating. “I’m really excited to sing next to the Pope and sing in the Sistine Chapel. … I’m looking forward to seeing all the history of what’s over there,” he said. The students sing together as one big choir and in smaller chamber groups. There’s also a hand bell ensemble. They’ve hired a private orchestra to accompany them in one performance in Rome, Melvin said. Video by Mark Eades, ocregister.com/video.