(CBS News) ROME - This week, St. Peter's Basilica was filled with 42 voices from Houston. The choir of St. Anne's Church received a rare invitation to celebrate the 500th anniversary of the basilica's choir. The trip was planned years ago. But just before they left Texas, the singers heard the news that they would miss the pope, but they would witness history.
CBS News caught up with the sound of St. Anne's choir in a Rome hotel as they rehearsed for their date in St. Peter's. Jim Ross has led the choir for 20 years.
"The first time we came to Rome was in 2005 in April ," he said. "Pope John Paul II died on April 2nd, so we came here two days after he died.
"We thought, 'Well, we're going to miss this,'" Ross continued. "But then it was very serendipitous. Just by chance they knew we were here, and I got a call the night before asking if we would sing. And I threw my hands and I said, 'Would I consider? This is incredible.'"
When Ross got the invitation, he could hardly believe it. "It's true. And so we came again, you know, planning, hoping to see Pope Benedict XVI after the mass, but however he resigned two days before we left."
It would seem like Ross doesn't have luck with popes. "I've been asked often, 'Will you come back again?'" said Ross. "And I'd like to think third time is the charm."
Steve Simko is a children's cancer doctor in Houston. For his first trip to Rome, he learned a Gregorian chant from around the 10th century.
"Gregorian chant is a very linear thing," he explained, "where you often will sing a lot of notes for one syllable," said Simko. "For instance, would you object if I sang?"
We let him sing his Gregorian chant of "lord have mercy." Afterwards, he said: "It's almost as though our prayers are singing themselves."
As for the feeling he gets when he sees and hears his choir inside St. Peter's, Ross said: "There's no way to believe that I'm here in St. Peter's with the people I've known so long. It's an out of body experience, out of time, out of space, because we are just ourselves as a group, but we've been transported to this place.
"We're singing the same music we sing for the community of St. Anne's on a Sunday, and yet we're doing it in this incredible space, with all of these people here, with all of the hierarchy -- and in front of this altar, the altar and the chair."