Heitor Villa-Lobos is one of the most prominent Brazilian composer of classical music. He also maintained a close connection to Brazilian folklore, which is reflected in his works. He has composed a suite with various choros and has also worked elsewhere on the fusion of Brazilian and classical European music.
His twelve etudes are among the most famous pieces in the classical guitar repertoire. Especially the first two etudes feature a very rigid technical workout. Etude N#1 puts the focus on the right hand, featuring a permanent pattern almost completely throughout its entire length. I recommend it to intermediate to advanced fingerstyle players to stabilize and improve their technique.
Watch classical guitar trailblazer Andres Segovia perform a dazzling version of the Etude N#1 :