Walter Burle Marx (1902-1990) was a Brazilian conductor/composer/pianist who was a close friend and a big advocate of Villa-Lobos. He conducted important Villa-Lobos premieres in Brazil and America, including important concerts at the 1939 World's Fair in New York. I recently came across his interesting guitar pieces on a recording by Stephen Aron, and look forward to listening to more Burle Marx.
Roberto Burle Marx (1909-1994) was a great Brazilian landscape architect who designed the gardens at the Museu Villa-Lobos. Though this isn't mentioned in his (otherwise very informative) Wikipedia article, the two were brothers.
I discovered this when I came across the cool story "Esthetics: Brazil's Marx Brothers", in the July 21, 1967 issue of Time Magazine. This was indeed an accomplished and interesting family, and distantly related to Karl Marx as well.