Joao Carlos Martins was a quirky brilliant and accident-prone pianist. Now he’s turned to conductying. “In Brazil, we only have orchestras sponsored by the federal and state governments. So when I took my first conducting lesson three years ago, I wanted to show that I could create a private orchestra that could support itself on private sponsorship and box-office receipts. Nobody believed me. But during 2006, we gave 50 concerts in Brazil.”