Karl Ignaz Weigl (2 February 1881 – 11 August 1949) was an Austrian composer, noted for his string quartets and symphonies. He was born in Vienna, the son of a bank official who was also a keen amateur musician. Educated at the University of Vienna and the Conservatory of the Gesellschaft der Musikfreunde, he went on to study with Alexander Zemlinsky, who was a family friend. Although Weigl never abandoned writing tonal compositions and did not believe in the twelve tone system, Weigl nevertheless became friends and associates of both Webern and Schönberg. In 1903, the three founded the Vereingung Schaffender Tonkünstler which dedicated itself to presenting concerts of important modern works like those of Mahler, Reger, Strauss, Pfitzner, Schoenberg, and Zemlinsky. Mahler, then the director of the Vienna Court Opera, engaged Weigl as his rehearsal conductor. There, he coached such legendary singers as Leo Slezak, Lotte Lehmann and Selma Kurtz. Throughout this period up until the outbreak of WWI, Weigl worked diligently composing works in many genres. When the Nazis occupied Austria in 1938, Weigl emigrated to America, together with his second wife, musician and composer Vally Weigl (nee Pick) and his son. There, he obtained a number of increasingly important teaching posts: at the Hartt School of Music, at Brooklyn College, at the Boston Conservatory and, from 1948 on, at the Philadelphia Academy of Music. He died in New York after a prolonged battle with bone marrow cancer.