The film features many pieces by Wolfgang Amadeus Mozart. Notable examples include the aria "Non Più Andrai" from the opera The Marriage of Figaro, the andante movement from Eine kleine Nachtmusik, the first movement of Mozart's Piano Sonata No.11, K331 (best known for the third movement, the Rondo alla turca), the Posthorn Serenade, K320 and a Rondo in D, K382. In the Hopscotch - Criterion Collection DVD special feature "Introduction by Neame & Garfield", director Neame stated that Matthau's agent made the suggestion that they put in some Mozart because this would greatly please Matthau. As they looked into this, they realized that it would enhance the movie if Kendig loved Mozart. Ian Fraser was the arranger and found many sections of Mozart that fit the movie, but they could not find anything to go with Kendig typing. They asked Matthau; he brought in some Mozart that went perfectly with it.