The dance drama “Astra,” a waltz-ballet, is based upon a new libretto that draws on dark themes from Edgar Allan Poe’s stories “Ligeia” and “Metzengerstein.” It is danced to an original score by Regan Remy that evolves from the 19th century classical style and orchestration of imperial Austria to the 21st century’s cosmopolitan and transcultural Gothic form, the two however united under the discipline of the waltz.