“We really took our time and went all out with the production, in house,” emails El Combo Oscuro capitán John Dell about La Danza de las Sirenas. “Glad we got to include a few slow burners that have been cooking a while.” Like tamales for Christmas, the sextet’s debut full-length makes a case for Cumbia Capital ATX with lit cumbias, lean mambos, and sidewinder chichas. Guitars and vintage organs wheedle and weave above a ringing percussive backdrop as warm, mysterious, and psychedelic as magical realism. Grupo Fantasma satellite Money Chicha and DJ Beats of Burden pachanga in support. ¡Órale!