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:
House_music

Context:
In the U.S., the music was being developed to create a more sophisticated sound,[citation needed] moving beyond just drum loops and short samples. In Chicago, Marshall Jefferson had formed the house group Ten City Byron Burke, Byron Stingily & Herb Lawson(from "intensity"). New York–based performers such as Mateo & Matos and Blaze had slickly produced disco house tracks. In Detroit a proto-techno music sound began to emerge with the recordings of Juan Atkins, Derrick May and Kevin Saunderson.

Question:
where was marshall jefferson based?

Chicago