Returning to Washington under the baton of former NSO principal conductor Iván Fischer, known to D.C. audiences as “a meticulous musician [with] an anarchic disdain for decorum” (New Yorker), the Budapest Festival Orchestra presents a novel program that pairs mainstays of the Mahler and Dvořák catalogues with underexposed works by the two late-Romantic composers. The “expressive colours” (BBC Music Magazine) of German contralto Gerhild Romberger bring to life the powerful emotions of Mahler’s Kindertotenlieder.