Matt Caughthran didn’t need to remind the crowd inside La Cita to show their enthusiasm. even if Mariachi El Bronx were filming for a new music video inside the sold out, Saturday night show. This crowd, packed close to the narrow stage inside the downtown Los Angeles bar, was already hyped. And “Bandoleros,” from the forthcoming album, Mariachi El Bronx IV, is a jam with a cumbia rhythm that automatically gets people dancing.