Portuguese guitarist Marta Pereira da Costa makes a rare appearance in New England, wrapping up a ten-day tour that also saw her performing at Lincoln Center, South by Southwest, and the Portuguese embassy in Washington, DC. She’s actually the first and, to date, only female guitarist to professionally play the Portuguese guitar, a 12-stringed instrument most often associated with fado music. (Fado is a very dramatic genre of balladry that normally features diva-like singing over an all-male band.) In other words, she’s kind of a big deal.