You may have heard of the annual Carnival of Rio de Janeiro, Brazil. For almost a week, normal life stops and Rio turns into a city of music and dance. The highlight is the competition of samba schools. 

A samba school is a community organisation where people come to dance and sing on the beats of a huge percussion section (up to 500 players!). Each samba school is associated with a neighbourhood in Rio, and consists of a percussion section ('bateria') and a number of dance sections ('alas').

Some famous samba schools are G.R.E.S. Estacão Primeira de Mangueira, Mocidade Independente de Padre Miguel, G.R.E.S. Portela and G.R.E.S. Academicos do Salgueiro. There are many more! Each year, each samba school selects a theme ('enredo') and composes a song ('samba de enredo') to go with it. People spend many months preparing costumes and floats to parade during their hour of glory in the competition.

The music consists almost entirely of percussion instruments - the effect is quite overwhelming. The only melodic instrument is the 'cavaco' (also called 'cavaquinho'), a small guitar with four steel strings. No other instruments are allowed in the Carnival parade.