Awkward and unhip, the accordion is the unlikely musical glue that bonds Mexican conjunto and banda, Czech and German polkas, sad Cajun waltzes and furious zydeco two-steps — in other words, the major food groups of Texas roots music. Despite the instrument's oompah-band image outside the state, programs such as Texas Folklife Resources' "Big Squeeze" contest have made great strides in making the accordion appealing to young Texans. One example is 2007 Big Squeeze runner-up Robert Vega, who now fronts his own family band, Houston's Promesa Mortal, with sister Tina as one of the few female bajo sexto players in regional Mexican music. Winners of Sunday's auditions (co-sponsored by the Houston Press music blog Rocks Off) get $1,000 in cash, a brand-new Hohner accordion, recording sessions and a spot at TFR's annual Accordion Kings & Queens, the festival that packs Hermann Park's Miller Outdoor Theatre every summer. Contestants should arrive by 2 p.m.