"his famous Polonaise"

Henryk Wieniawski (1835-1880) was a Polish composer and violinist. Although his father converted to Catholicism, he was of Jewish descent, therefore it is probable that any niece of his, if discovered, would be sent to Auschwitz during the Nazi occupation of Poland. He published two Polonaises and wrote a third.

Wieniawski's Polonaise No. 1 in D, Op. 4 on Spotify

Wieniawski's Polonaise Brilliante No. 2 in A, Op. 21 on Spotify