Brazilian recording artist Armandinho Macedo (known in Brazil by his first name) is a leading figure in a style of electric music known as frevo—an uptempo march originating in the city of Recife. He also plays another style called chorinho. In the above left photo, he appears to be playing an 8-string traditional Brazilian-style bandolim with a pickup. He's reportedly also used an Ovation mandolin. And above right, he's pictured with a 10-string semi-hollow electric built for him by luthier Jorge Augusto.
Armandinho is also known as one of the foremost players of the guitarra baiana (Bahian guitar)—developed by his father, Osmar—which is, essentially, a 5-string solidbody electric mandolin. That's the white instrument at left, although I don't know who built it. To see another of these, check out my page on another Brazilian player, Heraldo Melo. (Bahia is a state in northeast Brazil; here's an article on recent trends in Bahian music.
In addition, Armandinho continued with another of his father's innovations: the trio elétrico—a group (not necessarily a trio) that plays outdoors on a sound stage built on top of a truck, as pictured. And you thought only the Partridge Family did that. Apparently the term trio elétrico may refer either to the group, the truck itself, or the loud, lightning-speed style of frevo that such groups play.
In November 2002, Armandinho performed at the Kennedy Center in Washington, D.C. If you have a broadband connection, here's a link to a video of the performance. And here is an MP3 clip of his solo on "Baiana Brejeira."
If you're not confused enough already, there was another famous Brazilian mandolinist named Armandinho; he played choro music and was active in the first half of the 20th century.