Schumann, whose partial Jewish heritage made him particularly vulnerable to Nazi anti-Semitic persecution, nonetheless continued to perform. He felt a measure of security because he had blue eyes and did not appear to be Jewish. He sometimes tested his luck, removing the yellow star Jews were required to wear for identification and, on at least one occasion, daring an SS officer to arrest him.
"You should arrest me, sir, for I am underage and Jewish to boot," he told a Nazi who attended one of his shows. The officer could only assume the young musician was joking and did nothing, according to an account in the volume "Different Drummers: Jazz in the Culture of Nazi Germany" by Michael Kater.
Schumann was ultimately arrested in 1943, charged with performing degenerate music and with having relationships with Aryan girls.
He was set to be deported to Auschwitz, the Nazi death camp in Poland where more than 1 million Jews and other victims were murdered during the Holocaust. He said that his father, a veteran of World War I, interceded on his behalf and succeeded in having Schumann sent instead to Theresienstadt, the camp-ghetto in Czechoslovakia.
Also known as Terezin, Theresienstadt was used by the Nazis as a propaganda tool to deceive observers including the Red Cross about the true nature of concentration camps.
"We had music there and cabaret in order to mislead the people," he told an interviewer for the book "A Woman at War: Marlene Dietrich Remembered." "I played percussion in a big band called the Ghetto Kennel." He also performed with a group known as the Ghetto Swingers, replacing a drummer who had been deported to Auschwitz.
Schumann, too, was sent in 1944 to Auschwitz, where guards required him and other imprisoned musicians to perform for their captors' entertainment.
The musicians were ordered to play music from operettas and military marches for hours as new arrivals received their tattoos, as well as when condemned inmates were led to the gallows or to the gas chambers. A favorite number among the guards was the folk song "La Paloma."
Schumann told Michaela Haas, author of the book "Bouncing Forward: Transforming Bad Breaks Into Breakthroughs," that because of his stature at the camp, guards allowed him extra clothing and provisions that helped him survive.
He was transferred to and then liberated from a subcamp of Dachau in Germany, where he nearly died of illness. His parents survived the war, but much of his family perished.
After the war, Schumann returned to Berlin and performed with marquee names including Fitzgerald and Dietrich, who he said had been "a superstar to me, comparable only to Greta Garbo" when he was young. During Hitler's rise, the German-born Dietrich became a forceful opponent of Nazism and obtained U.S. citizenship.
"Above all, I thought very highly of her, being a German and a star like she was, that she was against Hitler," he said. "Many, many actors went along with it and betrayed their Jewish colleagues. I really thought a lot of her for being so much against that."
Seeking to escape his memories of the Holocaust, Schumann lived for a period in Australia, where he worked at a jam manufacturing plant and performed onstage before resuming his music career on cruise ships and in Berlin. He told Haas that he wished to be known as "a musician who survived the concentration camp. Not a Holocaust survivor who happens to make music."
Schumann was predeceased by his wife, Gertraud, who also was a Holocaust survivor. A complete list of survivors was not immediately available.
Schumann titled his memoir "The Ghetto Swinger: A Berlin Jazz-Legend Remembers" and continued performing well into old age.
"I have at least one good reason not to play 'La Paloma,' but also a thousand reasons to play it - every single person in the audience," he said. "It's not the music that's at fault."