We've notice that the good, far out folks of the South Texas Polular Culture Center (Tex-Pop for short) have been putting on an increasing amount of events over the past year or so, and that is music to our ears. The institution, as hippie as they come, exists to “Collect, document, exhibit, preserve, interpret, and celebrate South Texas music and music-related art and history.” It's a noble mission, but the organization isn't just some hushed hall where hangers-on reminisce, it's a living a breathing force in San Antonio music. This Sunday, in a special showcase, visitors will be treated to an old fashioned song swap, the likes of which helped birth some of the most beloved Texas (and other) tunes. Participants in this particular swap are veteran Texas songwriters Al Staehely, Freddy Steady, and Rex Foster.