For the past 20 years, through revolving lineups, Richmond hometown favorite Bio Ritmo has proven to be one of the most innovative salsa bands in the country, if not the world. This straight-up salsa track, "La Muralla," or "The Wall," is the B-side of a 45 released in December by New York's Electric Cowbell Records, which is run by percussionist Jim Thompson, a former member and Bio Ritmo founder. Along with the instrumental A-side ("Dina's Mambo"), it gives us a peek at the 12-inch vinyl album to be released later this year. "La Muralla," a song about the imaginary walls we build in our lives, also will be featured on Electric Cowbell's (CD and digital) compilation album coming out at the end of June called "101 Things to Do in Bongolia." Two decades on, Bio Ritmo remains dedicated to exploring music's genre-bending potential, not merely the more cliqueish salsa dance club scene.