The sound that most people associate with Brazil's Carnival is samba - preferably played at deafening volume to the accompaniment of a huge drum section.

Rupert Carey: "Brazil is determined that this time it will be the biggest and best yet"

Samba is the musical basis of Carnival celebrations in Brazil's two biggest cities - São Paulo and Rio de Janeiro.

But contrary to what most people around the world may think, the Rio Carnival is not a gigantic street party.

In fact, it is a tightly organised competition between samba schools from the city's many shanty-towns.

Each school chooses a theme for its display and tries to outdo the others with the extravagance of its brightly-coloured floats and costumes.

The place where the parades take place - the sambadrome - is open only to paying members of the public.

Thousands join the party in Salvador

If you are looking for dancing in the streets, you have to go elsewhere.

Up in the Northeast of Brazil, they dance to a very different beat.

This is what's known as axé music, a funky rhythm strongly associated with Carnival in the city of Salvador.

Here, the festival is a far more chaotic, anarchic affair than it is down south.

Pop groups trundle through the streets on top of giant sound trucks. Huge crowds dance along behind them, sweating in the tropical heat.

Northeasteners love their celebration so much that many cities have started holding extra out-of-season Carnivals.

Elsewhere in Brazil, the pre-Lenten festival takes many different forms. In smaller cities, young people spend all night at special Carnival balls.

But some Brazilians actively dislike Carnival. They feel that the celebrations are pointless, excessive, indecent or all three.