I want to know the answer to the following question:
In 2005, what anniversary was house music celebrating?
All the background I'm provided with is that "Chicago Mayor Richard M. Daley proclaimed August 10, 2005 to be "House Unity Day" in Chicago, in celebration of the "21st anniversary of house music" (actually the 21st anniversary of the founding of Trax Records, an independent Chicago-based house label).". Is that enough to answer the question?