When Rodrigo and Gabriela met, they were 15-year-old Metallica fans taking the same drama class in Mexico City. Now they're globe-trotting guitar gods, bringing classical picking to the masses by enriching it with fleet flamenco solos and a little of that heavy metal energy. Their back-and-forth, Flatt & Scruggs-style speed trials have added frilly, ebullient tension to blockbusters ranging from Pirates of the Caribbean to Puss in Boots. This crash course, however, emphasizes live performances that display the duo's incredible dexterity and chemistry.