Natascia Diaz. (Eli Meir Kaplan)

NEW YORK — One of the refreshing aspects of a cabaret evening with Natascia Diaz is that the stories she tells between songs aren’t about her — they’re about the songs.

Diaz, a fixture onstage in both New York and Washington — her recent D.C. credits include appearances as Anita in Signature Theatre’s “West Side Story” and Bianca in Shakespeare Theatre Company’s “Othello” — showed off her melodic versatility in a delightful evening of pop, country and show tunes Wednesday at the popular Broadway supper club Feinstein’s/54 Below.

That the set could work in the songbooks of Johnny Cash, Jacques Brel, Joni Mitchell and the Broadway team of Tom Kitt and Brian Yorkey and still feel like a cohesive statement speaks both to Diaz’s range and her agility at interpretation. The level of intelligence and commitment she displays in a full-length play or musical is compressed with consummate skill and technique over the arc, even, of a four-minute song.

Accompanied on guitar by the accomplished Steve Walker and, later, by Michael Pemberton, the engaging Diaz began the set with works by Mitchell (“Flight Tonight” and “Woodstock”) and moved on to Dolly Parton (“Jolene”) and Cash (“The L & N Don’t Stop Here Anymore”). Then she invited onto the stage her sister Katya Diaz with her partner, Chris Hierro. The couple, who call themselves Break Out the Crazy, performed a pair of their sensual, original pop-inflected numbers, “Two Is Better” and “Hold On,” before Diaz joined them for a resonant third “Crazy” piece, “You Are Everywhere.”

Natascia Diaz’s penchant for drama — a keen sense, always, of the special character of the story she’s spinning — came even more intensely to the fore in the sequence of musical-theater songs that made up the latter portion of the evening. A version of “Solla Sollew,” from Stephen Flaherty and Lynn Ahrens’s “Seussical” (and in which she appeared on Broadway) conveyed the melody’s embracing warmth, and her delivery of Brel’s “Ne Me Quitte Pas” occurred with the color of a darker passion. Renditions of “I Miss the Mountains” from Kitt and Yorkey’s “Next to Normal” and “Happy Birthday Darling” from an ill-fated 1990s musical adaptation of the novel “Bright Lights, Big City” allowed Diaz to sing in her emotional sweet spot, that being a plaintive soulfulness.

Her conversational manner is that of a friend who’s been through a few things and now wants to pull up a chair next to you, and share what she learned. It’s not confessional, though. It’s through the music that she really tells you who she is.