Among the distinguished Jewish musicians in fin-de-siècle Vienna was the Rosé family (see e.g. here).
Arnold Rosé (1863–1946) (here, and wiki), led the Vienna Phil from 1881 to 1931. Having worked closely with Brahms (!), he married Mahler’s younger sister Justine. Meanwhile he led the Rosé quartet from 1882 to 1938—to supplement my post on Late Beethoven quartets, here are the opening movements of their 1927 recording of the C♯ minor quartet:
Alma Rosé (1906–44; see e.g. here, here, and wiki), the niece of Mahler, named for his wife, was also a violinist. Here are father and daughter with the slow movement of the Bach double violin concerto in 1929:
In 1932 Alma formed the salon orchestra Wiener Walzermädeln.
Arnold gave his last concert with the Vienna Phil on 16 January 1938, playing Mahler 9 under Bruno Walter. But after the Anschluss, further devastated by the death of his wife Justine, he retreated to London with their daughter Alma.
But soon after reaching safety there, Alma made the fateful decision to try and resume her career in Holland. Fleeing to France upon the Nazi invasion, she was captured in 1942; after a period interned in Drancy, she was deported to Auschwitz, where she led the Mädchenorchester (see here, here, and wiki), before losing her life in 1944, aged 36.
Camp inmates like the musicians serving the whims of their Nazi tormentors (among many sites, see e.g. here and here) constantly had to negotiate impossible moral decisions in the faint hope of survival. Among the survivors was Fania Fénelon (here, and wiki), whose autobiography gives an unflattering portrayal of Alma, and downplays the bond between the musicians; as explained by Michael Haas, her account was disputed by other survivors such as the wonderful Anita Lasker-Wallfisch.
And there’s a recent Polish dramatisation of Alma’s story by Bente Kahan.
Arnold Rosé survived the war. In 1946 the Vienna Phil sought to reinstate him as leader, but he refused on the grounds that over fifty Nazis still remained in the orchestra (see e.g. here, and wiki). Heartbroken at the loss of his wife and daughter, he died that same year.