In 1943, German SS officers in charge of Auschwitz-Birkenau ordered that an orchestra be formed among the female prisoners. Almost 50 women and girls from 11 nations were drafted into a band that would play in all weathers marching music to other inmates. They were also made to give weekly concerts for Nazi officers, and individual members were sometimes summoned to give solo performances. For almost all of the musicians chosen to take part, being in the orchestra saved their lives. But at what cost? Sebba draws on meticulous archival research and exclusive first-hand accounts to tell the full and astonishing story of the orchestra, its members, and the response of other prisoners for the first time.