Thanks to a certain video game, everyone from your great uncle to the six-year-old who lives next door now claims to be a master of the guitar. It might be a relief, then, to be reminded what the guitar can do in the hands of people who can, you know, strum in todays case, those of the capable Brazilian string quartet Quaternaglia. João Luiz, Fabio Ramazzina, Paola Picherzky and Sidney Molina have spent the past 15 years together cultivating the art of contemporary classical guitar, touring the world as they perform songs by the likes of Sérgio Molina, Egberto Gismonti and Joaquín Rodrigo. You might feel a little demoralized the next time you step up to the PlayStation, but theres nothing wrong with a little respect for the guitar. 8 p.m. Emerson Unitarian Universalist Church, 1900 Bering. For information, call 713-665-2712 or visit www.guitarhouston.org. $20 to $30.