 He taught at the Juilliard School from 1924, heading the violin faculty until his death of cancer at age 46 in 1934.In 1933, when he was already dying, he helped Szymanowski complete his Second Violin Concerto and gave the premiere; when published (after Kochanski's death), the score bore a dedication to him.A non-religious ceremony was held at the school, attended by 1,500 people; his pallbearers included Arturo Toscanini, Frank Damrosch, Walter Damrosch, Jascha Heifetz, Vladimir Horowitz, Fritz Kreisler, Serge Koussevitzky, Leopold Stokowski and Efrem Zimbalist.