Most people have heard of samba and bossa nova, or of Heitor Villa-Lobos, who introduced the rhythms of Brazilian popular music to a classical audience, but they are only the tip of a very large iceberg of genres, styles and individual talents. Music - heard in bars, on the streets, car radios, concert halls and clubs - is a constant backdrop to social life in Brazil, and Brazilians are a very musical people. Instruments help but they aren't essential: matchboxes shaken to a syncopated beat, forks tapped on glasses and hands slapped on tabletops are all that is required. And to go with the music is some of the most stunning dancing you are ever likely to see. In Brazil, no one looks twice at a couple who would clear any European and most American dance floors. You don't need to be an expert, or even understand the words, to enjoy Brazilian popular music, but you may appreciate it better - and find it easier to ask for the type of record you want - if you know a little about its history