MADRID — At first the soldiers of the Red Army found almost nothing when they reached the camp in the southwest of occupied Poland that January. The retreating Nazis had blown up its crematories, dismantled its gas chambers; the prisoners had been marched west, in the freezing cold. Only later, as the Soviets liberated Auschwitz 75 years ago Monday, did they discover the last, straggling survivors, too ill or young to leave the inferno where at least 1.1 million people were murdered, 90 percent of them Jews.

Immediately after the war, writers and philosophers maintained that the death camps defied representation; no art could ever do justice to their horrors, and even the concept of poetry after Auschwitz, in Theodor W. Adorno’s notorious phrase, had become “barbaric.” Yet survivors themselves, as early as Primo Levi’s 1947 memoir, “If This Is a Man,” have forced themselves to make sense of the horrors they endured in art — and as Auschwitz recedes into historical distance and the last survivors disappear, there are voices even the greatest skeptic of representation cannot afford to tune out.

One is the self-taught Austrian artist Ceija Stojka (1933-2013), a member of the Roma minority (sometimes derogatorily called “Gypsies”), who turned the ordeals of the camps into an art of immense power. At 10, she was deported to Auschwitz, the first of three camps she would outlast. She slept on the pathway to the gas chambers, and hid among heaps of corpses; she survived by eating tree sap.