A trombone sounds a sour note, which is inspected by Oswald the Lucky Rabbit and sucked back into the trombone again in The Bandmaster (1931).
You’ll notice the wavy outlines in the first frame from the vibrations of the trombone music.
The “artists” listed in the credits of this cartoon are Tex Avery, Les Kline, Ray Abrams, Pinto Colvig, Manuel Moreno, Chet Karrberg and Clyde Geronimi. Karrberg’s life was cut short. He died on August 7, 1931 at the age of 21. He came down with pneumonia before a heart attack killed him. He had only graduated from high school in Asbury Park, N.J., in February 1929 and then got a job working on Krazy Kat cartoons with Bill Nolan.