Each Spring, the Guadalupe Cultural Arts Center celebrates the local genre with a five-day festival showcasing internationally renowned and local artists (most often those two overlap). But before we go any further, let's debrief for out-of-towners and locals who've never had a strong grasp on the differences between the two. Conjunto is the progenitor, born at the turn of the century when German settlers brought the accordion and oompah rhythm of the polka to the norteño music and bajo sexto of northern Mexico and Texas. Tejano is also a cross-cultural invention, merging conjunto with the horn section of orquesta and the dominant styles of post-war America — rock 'n' roll, blues and soul. This year's festival is slated for May 13-17 in Rosedale Park, a perfect time and place for two-stepping to this music born in the Rio Grande Valley, Corpus Christi and above all, San Anto. Rosedale Park, 340 Dartmouth St., (210) 271-3151, guadalupeculturalarts.com.