Paul Dessau, born December 19, 1894, in Hamburg, got in touch with the major works of musical theatre already as a child because of his family’s great interest in music (several family members worked as orchestra musicians and composers). He turned out to be a talented violin player but had to give up the instrument when a physician diagnosed him with impairment in his left hand. Dessau was then sent to Berlin to attend an apprenticeship as a director of music and piano lessons at Klindworth-Scharwenka-Konservatorium. In 1918/19, he found a job as répétiteur at Hamburg’s Stadttheater although he was just 18 years old at the time. At Stadttheater, he gained a lot of experience, not least from working with great artists like Giacomo Puccini or Enrico Caruso. At the same time, Dessau took composition lessons and strongly pursued his goal to become a composer on his own.

In 1915, Dessau was drafted for military service and was deployed at the French front, among other places, during World War I. Until the end of the war and his discharge from the army (where he was finally deployed to a military band because of an injury) in 1918, Dessau developed a strong repulsion against the "reign of terror of an unbound militarism" and against "everything that is called "drill"".

From 1918 on, Dessau landed several jobs as a répétiteur and director of music at well-known musical theatres all over Germany. In 1925, he earned the prize of music publisher Schott for his "Concertino" for violin, and two years later, his first symphony (in C) premiered in Prague. On June 21, 1924, he married actress Gudrun Kabisch. The couple had two children and separated in 1936.

Paul Dessau entered the film business in 1926 when Ufa entrusted him to conduct its Wiesbaden orchestra. After his return to Berlin, he worked as a conductor at several movie theatres. At the Alhambra movie theatres, he worked with the theatre’s chamber orchestra for two years, a time in which he also wrote a lot of original material that was enthusiastically received by critics and audiences alike. Indeed, music and film critics soon dedicated extensive reviews to Dessau’s music. Dessau himself saw his film compositions as an effective medium to make people familiar with sophisticated music. Thus, he told Reichsblatt in 1928: "The movie theatre, as a place of entertainment for the general public is obliged to a higher degree to work for the advancement of the musical education of the people than, for instance, the opera because the opera is still only accessible to a small number of people and only in a few big cities. And the most modern, current, and vivid art form, "the moving image", should be accompanied by the most modern and vivid musical language."

In the late 1920s, Dessau made his first sound film experiments and worked as a composer for numerous sound films, at first mainly film operettas and films about singers from the early 1930s on. Furthermore, he also composed the music for Arnold Fanck’s mountain films "Der weiße Rausch" ("White Frenzy"), "S.O.S. Eisberg", and "Stürme über dem Montblanc" ("Avalanche"). For the film, he experimented with a Welte-Mignon piano and a trautonium to realize electronic effects.

In 1933, Dessau emigrated to Paris because of his Jewish heritage. In Paris, he composed music for French feature films and mainly collaborated with fellow emigrants from the German film business like Kurt Bernhardt, Robert Siodmak, Max Ophüls, Fedor Ozep, or Detlef Sierck.

In Juli 1939, Dessau emigrated further to New York. Without a steady job and without contacts he scraped along with copying notes and texts of other composers and as a music teacher. His situation did not get better until 1942 when he met Bertolt Brecht who advised him to move to Hollywood. Besides his collaborations with Brecht, who also lived in Los Angeles at the time, Dessau was assigned by several film producers but only for instrumentation and orchestration jobs. Other composers occasionally hired him to do anonymous preliminary work when they themselves could not meet their deadlines for music scores – an unappreciative job that Dessau despised.

After 1945, Dessau received several credits as composer or director of music, for instance, for Edgar G. Ulmer’s "The Wife of Monte Christo" or "Winter Wonderland", directed by Bernard Vorhaus. His last work in Hollywood (again uncredited) was the composition, orchestration, and arrangement of music for Hugo W. Friedhofer in Victor Fleming’s film "Joan of Arc" in 1948.

In 1948, Dessau returned to Europe with his second wife, writer Elisabeth Hauptmann, and settled in East Berlin. During the following years, he again collaborated closely with Brecht who had also returned to Germany and composed stage music for several plays of Brecht’s Berliner Ensemble. However, Dessau’s and Brecht’s opera "Das Verhör des Lukullus" ("The Trial of Lucullus") was banned from performance in mid-1951 because the censors considered the music as "alien to the people and formalistic" – thus, the play did not enter the stage until late 1951 after numerous alterations.

During the following years, Dessau wrote numerous songs, dance scenes, and orchestral pieces. He did not compose any score music until the late 1950s, mainly for propagandistic documentary films by Andrew and Annelie Thorndike.

From 1952 on, Dessau served as a teacher at Staatliche Schauspielschule in Berlin-Oberschöneweide. In the same year, he became a member of Deutsche Akademie der Künste in Berlin and was its vice president from 1957 to 1962. In 1965, he also became a member of West Berlin’s Akademie der Künste but left the academy three years later under protest.

Basically, Dessau’s situation in the German Democratic Republic was ambivalent: With his appropriation of the twelve-tone technique and his dedication to Arnold Schönberg, he on the one side became the pinnacle of hope for the young avant-garde, but on the other hand he was attacked by the authorities and partly tacitly passed-by when his works were not performed – although he was officially honored with numerous national awards.

On June 28, 1979, Paul Dessau died in Königs Wusterhausen. In his will, he had made provisions that his memorial service should not take place as a state funeral but only in attendance of his family and friends.