Adolph Busch had already emigrated to the United States when he wrote the A-Major Clarinet Sonata. Shortly thereafter he revised the work once again until it was completed in its final form in spring 1941. Busch, a brilliant and sought-after solo violinist of the 1920s and 30s, concertized regularly in England and had become friends there with the clarinetist Reginald Kells, to whom he also dedicated the piece in three movements.