EAST COBB — What started out as a temporary job for Gregory Colson has turned into a six-year career directing the choir of Episcopal Church of St. Peter and St. Paul.

But at age 83, Colson has decided to retire as choirmaster and organist, ending a 43-year career in metro Atlanta that has included stints at several churches, including All Saints’ Episcopal and Peachtree Christian, and faculty positions at Georgia Tech, Emory, Georgia State and the Lovett School.

A free, farewell concert for Colson is scheduled for 3 p.m. Oct. 9 at St. Peter and St. Paul, 1795 Johnson Ferry Road near Bishop Lake Road, east Cobb. Colson will be directing the choir.

The featured work will be a four-movement cantata, “Discovery and Praises,” by American composer Conrad Susa, commissioned by Colson in 1966. Sue Goddard, a longtime colleague of Colson, will perform as a guest organist, along with other musicians.

“I had retired from another parish and they called me to come help them temporarily and it evolved into a very pleasant six-year term,” said Colson of his retirement.

“We’ve had such good success that it’s time for them to have a more fulltime person, because I’ve been completed part time.”

Isaac Brunson, the new choir director, is slated to formally start in November. Colson’s last church service at St. Peter and Paul will be Nov. 6.

Colson has conducted more than 500 concerts, many with members of the Atlanta Symphony Orchestra, Atlanta Ballet Orchestra, Georgia Symphony Orchestra, throughout the United States and Europe. His professional group, The Colson Chorale, was heard for 30 seasons in Atlanta.

At Georgia Tech, Colson served as head of the music department and founded the Georgia Tech Chorale. While teaching at the Lovett School in north Atlanta, he founded the Lovett Chorale.

He has held long-standing memberships in the American Guild of Organists, the Association of Anglican Musicians, the Royal College of Organists and National Trust of England.

“I started when I was 15,” Colson said of his career. “I started out as an organist and then later became choir director.”

A Kentucky native, Colson attended Western Kentucky University and earned master’s degrees in piano and church music from Peabody College in Nashville, Tenn. He met Betty, his wife of 57 years and a voice teacher, there.

Mastering music isn’t the only challenge Colson has undertaken in his life. Though diagnosed with polio as a child, Colson didn’t allow his physical ailments to block his love of music.

“The way he has overcome polio is one of his amazing qualities,” said choir member Steve Savage.

“One of Greg’s remarkable qualities is his brave conquest of the polio that left him crippled at age 16. Instead of letting this become an excuse, he has exhibited the positive attitude which has made his students and choristers admire him and wish to work for him. From his wheelchair, smiling and joyful, he radiates optimism, cheerfulness and enthusiasm.”

Though he hasn’t allowed polio to defer his aspirations, Colson acknowledged that it has begun to slow him down with age. Typically, he directs the choir from his place at the organ.

“I’m 20 years past retirement age and I have a polio leg from childhood polio that makes it difficult to get around. It’s just a natural process,” he said.

One of the things he said he most enjoys about choir directing is the fellowship among members, whom he said derive great satisfaction from leading a congregation in song. Colson said he has always challenged his choirs to perform difficult pieces but also made sure they had fun performing in special programs.

A choir, he said, spends more time at a church than perhaps anyone else because of the time needed to prepare. The many hours each day with his colleagues is what Colson said he will miss the most. He said he hasn’t decided what his plans are for retirement.

“There’s sadness any time you leave a place,” said Colson. “But there is no cloud over this.”