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:
Carnival

Context:
Carnival Tuesday hosts the main events. Full costume is worn, complete with make-up and body paint/adornment. Usually "Mas Boots" that complement the costumes are worn. Each band has their costume presentation based on a particular theme, and contains various sections (some consisting of thousands of revelers) that reflect these themes. The street parade and band costume competition take place. The mas bands eventually converge on the Queen's Park Savannah to pass on "The Stage" for judging. The singer of the most played song is crowned Road March King or Queen earning prize money and usually a vehicle.

Question:
What does each band base their costume presentation on?

theme