There are about 650 Stradivarius violins left in existence today. If one of them needs repair or restoration, their owners — wealthy collectors and world-class performers, mostly — call John Becker, a master luthier with a shop in downtown Chicago. How did a man who doesn’t play the instrument become the finest violin technician in the world? Elly Fishman explains:

He was drawn to the idea of working on rare violins — “I could see it was a craft” — and applied for a position at the prestigious violin dealer and restoration shop Bein & Fushi in 1979. Also located in the Fine Arts Building, Bein & Fushi ran a cutthroat apprentice program, but Becker’s talent was obvious from the start. “They said I was the best person they’d ever had,” he says.

When the top restorer left in 1982, Becker was tapped to fill his shoes. His first repair? The Adam, a 1714 Stradivarius violin named for a former collector. The business’s co-owner Robert Bein had given his employee The Secrets of Stradivari, a book by the acclaimed Italian luthier Simone Sacconi outlining the author’s best practices, and Becker absorbed them all. “I did some great work on that instrument,” he says.

In 1989, Becker took over as head of the entire workshop. Already renowned, Bein & Fushi became one of the world’s most prominent violin shops during Becker’s time there, thanks in large part to his work. “He was brilliant,” recalls Drew Lecher, who worked alongside him. “I guess you could say he had a Midas finger. If a violin didn’t sound right, he’d make it sound right. And if it didn’t look quite right, he’d make it look right. He was the standard-bearer.”