When Barbara Tracy sits at the organ in the First Presbyterian Church sanctuary and puts her fingers to its keys, it begins to sing.

Tracy, 67, has been First Presbyterian’s organist for 25 years, filling the church with sacred music that inspires song from the church’s choir and calls its congregation to prayer. She will celebrate her 25th anniversary Sunday with a 3 p.m. organ recital at the Cherry Street church.

“We don’t celebrate saints in our tradition, but if we did, we’d have a Saint Barbara,” the Rev. Tim Brown said. “She’s a wonderful Christian who’s been blessed with the gift of glorifying God through music.”

“I’ve been working with church music for 35 years, and she is by far the best organist I’ve ever been associated with,” said choir director Sharon Penley.

Tracy’s skill with the organ goes back to her teens in Bedminster, Pa., where she would occasionally fill in for her aunt, who was organist at the reform church she attended.

“I started playing the piano when I was six,” she said. “I always enjoyed it. My piano teacher taught me to play the organ. My aunt was a dairy farmer, and when they had to milk the cows and she couldn’t get to church, I filled in for her.”

Tracy came to Vicksburg in 1969, after her husband, Fred, accepted a job with the U.S. Army Corps of Engineers Waterways Experiment Station.

“I later took a job there, too,” she said, adding she has a degree in secondary education and physics from West Chester University in West Chester, Pa., and a master’s in engineering from Mississippi State University.

She was the organist for Westminister Presbyterian Church on Halls Ferry Road until 1987, when she was offered the organist’s position at First Presbyterian.

“The church got this organ in 1966, and it was built for this sanctuary,” she said. “You can feel it when you play. The music fills the church. They keep it in good shape, and that’s important.”

The difference between playing the piano and the organ, she said, is “when you lift the key on a piano, the sound continues. You lift the key on an organ, the sound stops. There’s fewer keys on an organ, but our organ has two keyboards and a pedal keyboard you play.”

Because playing the organ requires using the hands and feet, she said, “you get a lot of exercise. When you use your feet, it’s like jogging. It’s an aerobic exercise. It keeps you in shape.”

Playing the organ, she said, is like having access to an orchestra, because the stops, or tabs, along the sides of the keyboard, are pulled to re-create the sounds of other instruments.

“You have the instruments, but you don’t have 50 people with you at a time,” she said. “You can pull a tab for a trumpet, and the keys will produce a trumpet sound, and you can mix in other instruments while you play.”

Besides the sacred music she plays for the church, she enjoys playing Bach fugues.

“He understood the organ,” she said. “His pieces are fun to play and have lots of different voices — the different tones, pitches and keys. They’re magnificent pieces.”

She said her recital Sunday will feature a Bach fugue and other classical and contemporary music.

“When people think of organ music, they think that the composers have died,” Tracy said. “But many composers of organ music are alive and still composing. Playing a recital is different than playing for a service, because you don’t stop.”

She said she has been blessed at First Presbyterian to have a good relationship with Penley and Brown.

“We all work together, and it’s a joy to play an instrument like this one,” she said.

“With Barbara, it’s all about the work and not about Barbara,” Penley said. “It’s a pleasure to collaborate with her and being an equal with instrumental and choral music.”

“Her love of music is contagious, and it’s shown through her passion for excellence to the glory of God,” Brown said. “She has such a peaceful disposition that it inspires her to work well with others and brings out the best in everyone around her.

“If the Lord ever calls me to go somewhere else, Barbara had better be there.”