For an instrument that’s nearly as loathed as it is loved, the accordion managed to infiltrate the globe like one hot virus. For ten years, San Antonio’s International Accordion Festival has sought to inoculate music-lovers with the humble little instrument’s wide-reaching history and innovative uses. The keys to the accordion’s persistent existence? 1) It’s loud. 2) It’s portable. 3) It’s hard to destroy. From beginnings in China as a multi-reed instrument with bamboo pipes, combined with a later, similar instrument called the Bible Regal from medieval Europe, the accordion has wound up in Colombian folk music, Western “cowpolka” and Canadian klezmer hip-hop, to name a very few. Check out the old squeezebox in all its multicultural glory this weekend. Free, 6:30pm Fri Oct 15 — 9:40pm Sun Oct 17, Arneson River Theater 418 Villita, internationalaccordionfestival.org.