Question: In what year did the writer of the music of the Firebrand of Florence become a United States citizen?
Sentence (from "The Firebrand of Florence"): The Firebrand of Florence is a Broadway musical in two acts, written by Kurt Weill (music), Ira Gershwin (lyrics), and Edwin Justus Mayer and Gershwin, based on Mayer's play.
Relevant evidence: Yes