Karl Pilss was an Austrian pianist, conductor, and composer, and also a painter. He studied piano and music theory at the Wien (Vienna) Academy of Music from 1918-22 and composition from 1924-27. He also completed a study with conductor Robert Heger. Clemens Krauss engaged him as assistant conductor of the choir director Grossmann at the Vienna State Opera. In addition, he taught piano and music theory at the "People's Conservatory" founded by Grossmann, which later became the Wien Conservatory. In the 1930s Pilß, alongside his work at the State Opera, worked as director of studies 1934-66 for the Salzburg Festival.
Pilss’ compositional output included multiple works for winds, orchestral works, songs and choral works. Pilß also produced picturesque and graphic works of drawings, sketchbooks, watercolors, pastels and chalk drawings, and oil paintings.