John Richards described the achievement, which involved visiting 94 landmarks across the UK, as a "dream come true" and "absolutely wonderful".
The seventy-three-year-old, who plays the organ for Bethany Baptist Church in the Thornhill area of Cardiff, reached the end of the feat by playing on the organ at St Andrew's Cathedral in Inverness on Thursday.
Speaking on Premier's News Hour, John said: "It's a dream come true in a way because ...I never intended to do 94 in the beginning; that only crept on me after I had done 70 and I thought, 'Well, I can see the finishing line.'
John was encouraged to play music on cathedral organs by his second wife, Lyn, who saw he was "all over the place" following the death of his first wife and had stopped playing music.
He added: "She wrote to the director of music at Worcester Cathedral - that was the first one, on the 3rd of May 1997 - and asked him if I could play that organ.
"His name was Adrian Lucas and he replied; he said, 'Yes, you can'. That was the start of my journey."
Click here to hear John Richards speaking with Premier's Aaron James.