The Washington Concert Opera performs “Maria di Rohan.” (Don Lassell )

There were two reasons that Washington Concert Opera’s performance of Donizetti’s seldom-heard “Maria di Rohan” at Lisner Auditorium on Sunday proved a memorable experience, and they were closely related. A pair of opera-singing sisters named ­Costa-Jackson — soprano Marina and mezzo Ginger — turned a pretty, if thoroughly routine, bel canto potboiler into exciting music­making whenever they were onstage.

Of the two, Marina’s voice was the more attention-grabbing, ranging from a smoky chest register, through a gutsy, mezzo-ish middle voice, to a gleaming top with rock-solid high notes, clean coloratura, an ability to float beautiful pianissimo phrases and a heck of a trill. It was an exciting voice to experience and, in the romantically conflicted title role, she was able to infuse the empty melodramatics of the libretto with arresting emotion.

Sibling Ginger (in the trouser role of Armondo di Gondi) drew even more timbral variety and interpretive riches from the text. If her instrument was more compact than Marina’s, it was no less lovely, with its caramel coloration and impressive agility well into the upper reaches of the coloratura writing. And, of course, the Costa-Jacksons’ natural stage presence and character-appropriate youthfulness didn’t hurt their cause either.

The sisters weren’t alone in vocal excellence. Baritone Lester Lynch made the cardboard role of Enrico into something compelling, singing in long, elegant lines with a Verdian nobility and sonorousness to his sound. If Norman Reinhardt’s lyric tenor was smaller in size and impact than some of the other voices around him, his Riccardo was notable for a sweet-toned, Italianate finish and some lovingly caressed phrases. WCO Artistic Director Antony Walker conducted a lively, mostly tidy performance with his pickup orchestra of a score that never sounded less than reliably well-wrought, but also never fired the imagination, quickened the heart or lingered tantalizingly in one’s ears.