When the great Czech harpsichordist Zuzana Růžičková died last week at the age of 90, a black flag hung from the Rudolfinum, Prague’s premier concert hall, an emblem of triumph over adversity.

On Sunday night her star pupil, the Iranian-American harpsichordist Mahan Esfahani, went on the website of Yad Vashem, Israel’s official memorial to Holocaust victims.

“If you look up her name as a survivor, it connects you to all the forms she filled out,” he said.

“She filled out thirty forms! Imagine filling out thirty forms for your family. That must have been really tough. But that’s persistence. The lady never really gave up.”

After surviving the war, such persistence saw Růžičková make her way to Prague to study piano. There she saw a harpsichord class advertised.

“What is going on in the mind of a girl who’s been out of the concentration camps? She’s had all of her family murdered, Czechoslovakia has become Stalinist and pretty anti-Semitic, she comes to Prague, everything is grey and dark. What the hell are you doing picking up a flyer for a harpsichord class? What did it say to her? Was it something so distant from her reality and her surroundings? I never asked her this question.”

But Mr Esfahani feels he can provide the answer by reference to his own experience.

“I can tell you that for me (the harpsichord) was the most distant thing from my surroundings. I thought, if I’m going to get out of the reality I’m not a huge fan of right now, then I’ll play the harpsichord. That’ll lead me to something. I’d like to think that for her it was the same thing.”

As a harpsichordist, Růžičková had to face another enemy: the Early Music movement and its obsession with “authenticity” and period performance.

“Period performance,” according to Mahan Esfahani, “is what this guy from the library says it is, and if you disagree with that, then you can **** off.”

He is indignant at being asked by a music magazine why he chose to study with Růžičková when there were so many other disciples of Gustav Leonhardt, the god of authentic harpsichord playing, around.

“Růžičková’s power as an interpreter,” Esfahani writes in his introduction to her complete Bach recordings, “… lies in her conviction that current interpretation is unique to her as an artist and individual rather than depending on a school of playing.”

“She beat Hitler,” he beams. “You think she was going to let Leonhardt push her around?”