Ellie Goulding showed off her two sides — traditional singer-songwriter and modern-day pop star — at Merriweather Post Pavilion. (Kyle Gustafson/For The Washington Post)

On a video screen, Ellie Goulding materialized, her clothing white and her visage virginal. But as the music crescendoed, the pristine image dissolved into fragmented cuts of Goulding in black, her fingers extending from cut-off gloves. This yin-and-yang theme played out several times over the course of Goulding’s Monday night concert at Merriweather Post Pavilion — in the costumes of two dance-fighters, in lyrics like “Tell me, black and white, why I’m here tonight” — but for Goulding, the duality isn’t a Jediesque question of light vs. dark.

It’s between being a traditional singer-songwriter and a modern-day pop star, and more than any of her millennial peers, she balances both sides with aplomb.

Goulding sings like an English forest nymph who discovered dance music, says our critic. (David Roemer)

The 29-year-old Brit established her style on her debut “Lights,” an album full of dreamy synth-pop and Goulding’s striking voice. Breathy and quivering, Goulding sings like an English forest nymph who discovered dance music, and she sounds like no one else in pop. But until recently, her career moved in fits and starts, her albums never breaking through until savvy hitmakers added catchier singles for re-release. That changed with last year’s “Delirium,” as Goulding enlisted pop masterminds Max Martin and Greg Kurstin from the get-go, resulting in her highest-charting but perhaps least personal album.

The balancing act between the nuance of her early work and the un-subtleties of pop hitmaking carries over to her live show. Thankfully, her impressive voice was intact in concert. She doesn’t shy away from the birdsong of her upper register — her vocal runs are showier than those on record — and at times she performed accompanied by only guitar or piano.

Fans appreciated those intimate moments, but they’ve come to expect sensory-overloading shows from amphitheater-size pop concerts. By that measure, Goulding didn’t disappoint, flanked by a four-piece band, a trio of backup singers, a four-deep dance troupe and towering video screens that animated her face with laser lights and special effects.

But for every concession to convention, Goulding did something her own way. There were no spandex bodysuits — just a tank top, baggy cargo pants and Doc Martens boots — and although choreography isn’t her forte, she moves across the stage with charmingly corny, and endearing, dance moves.

When Goulding bantered with the crowd, she was reserved, restrained and very British, the lone exception coming when she hailed a fan who held a rainbow-colored sign bashing Donald Trump. “Screw that guy, seriously,” she laughed.

She then launched into best-friend anthem “Army,” its “When I’m with you, I’m standing with an army” chorus especially poignant a day after the Orlando nightclub shooting. Even in pop music, some things — like the choice between love and hate — are black-and-white.