I missed this NPR feature, from Performance Today, from 2005, on the Carnaval and the popular music of Brazil. Besides the Villa-Lobos piece played by pianist Luiz de Moura Castro and selections from the Obrigado Brasil project, you can listen to a quick rundown of important genres of Brazilian popular music: samba, choro, bossa nova, the music of Bahia, and capoeira.
Make sure you follow the link to the Performance Today page for Obrigado Brazil: Yo-Yo Ma's all-star Brazilian project. The Villa-Lobos piece is A Lenda do Caboclo, with Sergio & Odair Assad and Ma, but Villa's finger-prints are all over much of this music.
You can buy the original CD of Obrigado Brazil from Amazon.com: