Once a year, 250 students from five different schools gather to sing as one choir in the Sioux City Diocesan Catholic Choral Festival.
This year, St. Edmond Catholic School hosted the one-day event - something it only gets to do every five years.
Nicole Brown, vocal music director at St. Edmond, said Wednesday that it offers a rare chance.
"It's a really good opportunity to sing with a lot of people in a large setting," she said.
In addition, her students get to work with directors from other schools, as does she.
"It's a good learning experience for me and my kids," she said.
Seventy-five of the students in the choir are from St. Edmond. The balance are from Bishop Garrigan High School of Algona, Bishop Heelan High School of Sioux City, Kuemper Catholic High School of Carroll and LeMars Gehlen.
Liz Johnson, a senior at St. Edmond, spent Wednesday in rehearsal with her fellow sopranos.
In addition to the chance to sing with so many others in her voice range, she was happy to meet up with friends she has made during previous years.
"It's really nice," she said. "I've made a lot of friends."
Christian Matthews, a junior at Bishop Garrigan, enjoyed being able to work with new singing partners too.
"You're not with the same group," he said. "You get to hear what other voices sound like."
Matthews is a veteran of the annual event; he was having little trouble singing with the new group and looked forward to the performance Wednesday night.
"I've done this a lot," he said. "I tend not to get too nervous."
Andrew Last, an instructor in the vocal music program at Luther College, was this year's guest conductor. It was his job to bring it all together.
"You have five different choirs who have learned the same five songs," he said. "You only have a short amount of time to turn five into one."
He said the event offers the students a chance to experience what's going on at the other schools, as well as the experience of doing music that requires many more voices.
"They need the numbers," he said of those selections.
The students spent the day immersed in music; individual clinics were held for each voice range and then joint rehearsals combined the whole group.
In the evening, the students performed a concert for the public.