Eight years ago, Leo Geyer was at the museum that now stands at Auschwitz-Birkenau, when he got chatting to an archivist. It was a conversation that would change his life. “It was actually an accident,” says the musician and composer. “He just said in an offhand way that there were music manuscripts buried in the depths of the archive.” Geyer knew about the orchestras of Auschwitz concentration camp, “as most classical musicians do”, he adds. But he had no idea there were any manuscripts left after the Nazis tried to liquidate the camp before the arrival of the Red Army....