Her then husband, sculptor Bernard Kratko, introduced Kon to Isaac Leib Peretz and Kon set several of Peretz's works to music, including Treyst mayn folk (Comfort My People) and the play Bay nakht oyfn alten mark (A Night in the Old Marketplace).
He composed music for around 40 theater productions,[4] including Sholem Asch's Kiddush ha-Shem, Shakespeare's Shylock, Aaron Zeitlin's (Tseytlin's) Yidnshtot, Moshe Lipshitz' Hershele Ostropolyer, Dovid Bergelson's Di broytmil (The Bread Mill), H. Leyvik's Der Golem, and many others.
His opera David and Batsheba was written (with Moishe Broderzon) and presented in Warsaw in 1924, in a piano version.
He wrote the music for Boston, about Sacco and Vanzetti, Trupe Tanentzap, an Abraham Goldfaden spectacle, Napoleon's Treasure, based on a Sholem Aleichem story, and many others.
Beginning in 1934 he also worked in film; he composed the music for The Dibbuk and Zygmunt Turkow's Di freylekhe kabtsonim (The Jolly Paupers), among others.