The steelbands in Trinidad are huge orchestras, with up to 300 instruments which are solely composed of petrol drums called "pans". The musicians manage to obtain the most magical sounds and can even tackle symphonic music with them. During the Carnival, the musical bands flood the streets and wage fierce competition with one another. The film shows how the instruments are made and interviews the composers and arrangers. It also shows the great yearly contest in which 400 to 500 drums vibrate in front of delirious crowds.