His interest in music began not with pianos but with the viola and the violin. He studied at academies in Cologne and Detmold and, in his 20s, played guitar and mandolin in German dance bands.
He was playing Dixieland music one night when he spotted a woman on the dance floor. “I fell in love with her as soon as I saw her and said to my friends, ‘That is the girl I’m going to marry,’” he recalled in his memoir. Her name was Elisabeth Zillikens, and they married in 1954. Besides his son Michael, she survives him, as does a daughter, Ellen; seven grandchildren; and three great-grandchildren. Another son, Peter, died in 2019.
Tendinitis forced Mr. Mohr to give up performing when he was in his 20s, his son said, and he turned to pianos, answering a want ad from the piano manufacturer Ibach that led to an apprenticeship. Another advertisement, in 1962, sent him to the United States.
It said that Steinway was looking for piano technicians — in New York. A devout churchgoer, he had made a connection with a German-speaking Baptist church in Elmhurst, Queens, that showed him the ad. He contacted Steinway and was soon hired as an assistant to William Hupfer, the company’s chief concert technician.
Before long, he was tuning for stars like the famously eccentric Canadian pianist Glenn Gould, who came to New York to make recordings. (In Toronto Gould relied on another tuner, Verne Edquist, who died in 2020.)
Mr. Mohr not only worked on the piano at the recording studio, he also rode around New York with Gould. “He loved Lincoln Town cars,” Mr. Mohr wrote in his memoir. “That is all he would drive. He once said to me: ‘Franz, I found out that next year’s model will be two inches shorter. So, you know what I did? I bought two Town Cars this year.”