Eisler was born in Leipzig where his Jewish father, Rudolf Eisler, was a professor of philosophy. In 1901 the family moved to Vienna.

His sister was Ruth Fischer (Elfriede Eisler), a leader of the German Communist Party (KPD) during the 1920’s, and author of The Sexual Ethics of Communism, and Stalin and German Communism: A Study in the Origins of the State Party.

His brother was the journalist and Communist Gerhart Eisler who was believed to be a major Comintern agent operating under the name of Hans Berger. Louis Budenz, a former managing editor of the Daily Worker, called him, “the Number One Communist in the U.S.” in a speech in the fall of 1946. Time Magazine wrote of him, “He turned up in China, charged with purging the party of spies and dissidents, sent so many men to their deaths that he was known as ‘The Executioner'”.

During World War I Hanns Eisler served as a front-line soldier in the Austro-Hungarian army and was wounded several times in combat. Returning to Vienna after Austria’s defeat, he studied from 1919 to 1923 under Arnold Schoenberg. Eisler was the first of Schoenberg’s disciples to compose in the twelve-tone or serial technique. He married Charlotte Demant in 1920, they separated in 1934.

In 1925 Eisler moved to Berlin—then a hothouse of experimentation in music, theater, film, art and politics. There he became a member of the Communist Party of Germany. In 1928, he taught at the Marxist Worker’s School in Berlin and his son Georg Eisler, who would grow up to become an important painter, was born.

His music became increasingly oriented towards political themes and, to Schoenberg’s dismay, more “popular” in style with influences drawn from jazz and cabaret. At the same time, he drew close to Bertolt Brecht, whose own turn towards Marxism happened at about the same time. The collaboration between the two artists lasted for the rest of Brecht’s life.

Eisler wrote the music for several Brecht plays, including The Decision (1930), The Mother (1932) and Schweik in the Second World War (1957). They also collaborated on protest songs that intervened in the political turmoil of Weimar Germany in the early 1930s. Their Solidarity Song became a popular militant anthem sung in street protests and public meetings throughout Europe, and their Ballad of Paragraph 218 was the world’s first song protesting laws against abortion. Brecht-Eisler songs of this period tended to look at life from “below”—from the perspective of prostitutes, hustlers, the unemployed and the working poor. He worked with Brecht and the director Slatan Dudow on the documentary film Kuhle Wampe which was banned by the Nazis in 1933.

After 1933, Eisler’s music and Brecht’s poetry were banned by the Nazi Party. Both artists fled, first to Moscow where The Measures Taken was produced and staged.[2] Eventually, they sought refuge in the United States, along with other exiles fleeing Nazi Germany.

In New York City, Eisler taught composition at the New School and wrote experimental chamber and documentary music. Moving shortly before World War II to Los Angeles, he composed several Hollywood film scores, two of which—Hangmen Also Die! and None but the Lonely Heart—were nominated for Oscars. Also working on Hangmen Also Die! was Bertolt Brecht, who wrote the story along with director Fritz Lang.

In 1947 he wrote the book Composing for the Films with Theodor W. Adorno. But in several chamber and choral compositions of this period, Eisler also returned to the twelve-tone method he had abandoned in Berlin. His Fourteen Ways of Describing the Rain—composed for Arnold Schoenberg’s 70th birthday celebration—is considered a masterpiece of the genre.

Eisler’s two most notable works of the 1930s and 40s were the monumental Deutsche Sinfonie (1935-57)—a choral symphony in eleven movements based on poems by Brecht and Ignazio Silone—and a cycle of art songs published as the Hollywood Songbook (1938-43). With lyrics by Brecht, Mörike, Hölderlin and Goethe, it established Eisler’s reputation as one of the twentieth century’s great composers of German lieder.

Eisler’s promising career in the U.S. was interrupted by the Cold War. He was one of the first artists placed on the Hollywood blacklist by the movie studio bosses. In two interrogations by the House Committee on Un-American Activities, the composer was accused of being “the Karl Marx of music” and the chief Soviet agent in Hollywood. Among his accusers was his sister Ruth Fischer, who also testified before the House Committee that her other brother, Gerhart, was a major Communist agent. The Communist press denounced her as a “German Trotskyite.” Among the works that Eisler composed for the Communist Party was the Comintern March, “The Comintern calls you / Raise high Soviet banner / In steeled ranks to battle / Raise sickle and hammer.”