The first thing to know is that most traditional Brazilian songs are composed from two beats per measure. Most musical styles that arose from folk culture owe their form to several cultural expressions such as dance, singing, accent, and religious expressions; different people have different ways to express music. It is also important to know that most Brazilian rhythms have the stress on the off-beat, or nearly so. Despite correctly following the rhythmic subdivision, you could fail to reach a satisfactory result if you forget this detail.
The Bossa nova emerged around 1958 in Rio de Janeiro, and there is no doubt that it was the most famous Brazilian music style outside Brazil. Tom Jobim and João Gilberto, respectively the main composer and the best performer, revolutionized the Brazilian popular music through a new musical approach. There are three points that distinguish this music of the music from before: more sophisticated harmonies, melodies with longer notes, and lyrics which tried to show the love as a natural thing, with sadness, nevertheless, without an overwhelming feeling.