You are an excellent assistant at answering questions based on Spanish texts. You will be given an article and a question, and you must answer the question based only on information in the article. The response should be extracted from the context verbatim.

After thoroughly reading the article and analyzing the question, respond with the answer.

Title:
Classical_music

Context:
Classical music has often incorporated elements or material from popular music of the composer's time. Examples include occasional music such as Brahms' use of student drinking songs in his Academic Festival Overture, genres exemplified by Kurt Weill's The Threepenny Opera, and the influence of jazz on early- and mid-20th-century composers including Maurice Ravel, exemplified by the movement entitled "Blues" in his sonata for violin and piano. Certain postmodern, minimalist and postminimalist classical composers acknowledge a debt to popular music.

Question:
What type of music do certain composers acknowledge a debt to?

popular