Beginning in 1934, the Nazi government implemented a policy of "Gleichschaltung," which brought professional musicians into line according to race.

The music magazine "Das Deutsche Podium, Kampfblatt für deutsche Musik" ("The German Podium, Fighting Paper of German Music") increasingly lauded Heckmann: “… during the course of several months, he has won over a large base of friends and supporters … with his fine, well-trained tenor voice …” “… Willi Heckmann – an all-around musical talent … his volume fills the room … piano playing, a pleasant chord, well-trained vocals, Herr Heckmann has it all …”[1] Additional performances and engagements in Stuttgart, Gotha, Munich, Patenkirchen and Passau followed.

When the photography division of the SS photographed the "Gypsy Orchestra" on 30 July 1942 as it was led through the camp together with the recaptured prisoner Hans Bonarewitz, Willi Heckmann was in the front row, setting the tone.

Following his visit in the autumn of 1942, Heinrich Himmler ordered the establishment of a camp orchestra, which was assembled "with the help of Heckmann, Rumbauer and a Czech doctor.

"[3] His participation in the orchestra made Heckmann a kind of functionary among the prisoners, and spared him the harshest jobs in the concentration camp.

Years of heavy labour in the Mauthausen quarry left him with rheumatism and inflamed nerves in his shoulders and arms, which hampered his efforts to practice his profession.