Starting Wednesday, Philadelphia will host a national conference of opera companies.

One of the issues to be discussed will be developing new work. It's no coincidence that, during the conference, two of the city's major opera companies are presenting new work.

In the Kimmel Center's Perelman Theater, the Opera Company of Philadelphia is staging "Dark Sisters." It is the first of a long-term commitment by the OCP to stage at least one new opera every season for 10 years.

"Somebody asked me recently, 'what comes first, the music or the words?'" said OCP director David Devan. "I said, 'the money.'"

That prohibitive expense is the reason there are so many productions of "Carmen," "Turandot," and "Madame Butterfly" — they are well-trod chestnuts whose audiences are guaranteed.

"Dark Sisters," on the other hand, is a gamble. Set in a rural, religious community that practices polygamy, the children have been forcibly removed from their mothers by a state child welfare agency. The opera composed by Nico Muhly is based on a true story in Texas that dominated the news in April 2008.

"It's a contemporary issue," Devan said. "It's a religious practice that very much rooted in a particular place. For [Muhly], that place suggested a soundscape — a musical experience that was vast but intimate at the same time."

"Dark Sisters," co-commissioned by OCP, Gotham Chamber Opera (NYC) and Music-Theatre Group (NYC), will be presented at the Opera America conference in Philadelphia as an example of the opportunities and challenges inherent in developing a modern repertoire. Due to the prohibitive expense, new work is usually commissioned by two or three opera companies, making conferences like this critical for creating financial partnerships.

Two or three partnering companies means the new work is gauranteed at least two or three runs. "Dark Sisters" premiered in New York City. The second production in Philadelphia has been tweaked, and, critics say, improved.

Another example of new opera is "Slaying the Dragon," an original commission by Center City Opera Theater, having its world premiere run during the conference. It tells the story of a Grand Dragon of the Ku Klux Klan who, in his decling years, befriends a Rabbi, reforms his violent racism, and ultimately converts to Judaism. It's also based on a true story.

"If it weren't true, it would be unbelievable," Philadelphia-based librettist Ellen Frankel said. "The story itself strains credibility."

Center City Opera Theater has a deep commitment to developing new opera, working closely with composers and librettists for years, through edits and workshops. As soon as "Slaying" wraps next week, Frankel returns to another opera commissioned by CCOT, based on Jewish Golem stories.

"There are now about 1500 new American opera works that have been tracked by Opera America," said Frankle. "Most of which have been performed once."

By the time "Slaying the Dragon" ends its run at the Prince Music Theater on Sunday, as many as 40 visiting opera company directors will have seen it during the conference. Frankel hopes some will pick up the Dragon and extend its life in other cities.