If Dan Abrahamson offers to play J.S. Bach’s “Jesu, Joy of Man’s Desiring” for you on the magnificent pipe organ at First United Methodist Church, accept the offer.

The melody is so sweet, the sound issuing from the organ’s 7,442 pipes is so supernal, it will almost make you cry.

Seated at the organ’s console, pulling the instrument’s drawknobs and pressing its pedals with his feet, the silver-haired, 67-year-old is a master, producing music almost beyond compare.

“See how easy this is to do?” he says, smiling, as the last notes of Bach’s piece spread across the sanctuary.

Abrahamson is as much a fixture of worship at the church, 946 Vt., as the old, Lawrence-built Reuter organ itself. When he sits down to provide music for the 8:30 a.m. and 11 a.m. services Sunday, it will mark the completion of his 40th year as church organist. Abrahamson has played at the church’s early and late-morning services on at least 48 Sundays a year since Sept. 1, 1963.

This weekend, the congregation will say thanks for his contribution.

The Rev. Sharon Howell, senior pastor, has written a recognition liturgy that members will celebrate at both Sunday services — at which Abrahamson will play, as usual. It’s a litany in which representatives of the congregation will read tributes to Abrahamson, and Howell will lead a prayer of blessing for his music ministry. The chancel choir will sponsor a reception for Abrahamson from 10:30 a.m. to 11 a.m. in the church’s Brady Hall.

Howell speaks highly of Abrahamson, who worked at Reuter Pipe Organ Co. for more than 40 years, retiring on Christmas Eve 2001.

“Dan is an accomplished musician, yes, but he is absolutely one of the most faithful men I have ever met,” she says.

“He is Christ centered, he believes in servant ministry, he believes in God-centered worship, without question, and everything is just built around those understandings.”

Two of the pieces of music Abrahamson will play Sunday are among the first that he played at the church in 1963: “Benedictus,” by Alec Rowley; and Bach’s “Jesu, Joy of Man’s Desiring.”

Abrahamson, who has lived in Lawrence with his wife, Carol, since 1961, explains why he has remained as church organist all these years.

“There are three reasons why I’m still here. No. 1, this is a really cool instrument. It’s the largest organ in this part of the country. The second reason is I have always enjoyed playing the organ — it’s just a lot of fun,” he says.

“The third reason is that the people in this congregation are appreciative of good music and are very supportive. That makes all the difference in the world.”

He has no plans to give up as church organist any time soon.

“My wife and I have a saying: ‘I’ll keep playing as long as I play more right notes than wrong notes.’ I still am, so far,” Abrahamson says.