To most opera lovers, it’s as familiar as their own hands: the opera about an opera singer, Giacomo Puccini’s “Tosca.” To newcomers, it can seem the epitome of the heightened emotions and tragedy that are stereotypical of opera. And to musicians like those in Washington National Opera’s upcoming run of the opera, from May 11 to 25, “Tosca” represents a set of challenges that the audience may not even have considered.

“I’m trying to find the diva in her,” says Keri Alkema, one of the two sopranos who will share the title role. “Nowadays, it’s been beaten into me: Don’t be a diva. All of a sudden, I’m told I get to unleash her. That’s a little scary. Do I want to let her out?”