Alexandra Christoforakis, Raquel Gonzaelz and Aleksandra Romano in The Washington National Opera's production of "The Investment." (Scott Suchman/For The Washington National Opera)

The Washington National Opera’s American Opera Initiative commissions work from young composers. This is a good thing. I am not completely ready to embrace its premise that the best way to start is by commissioning 20-minute operas, because I’m not sure exactly what writing a short-form piece proves about a composer’s ability to write an evening-length work — any more than short-story writers are all necessarily great novelists. But thanks to this program, the company is giving out four commissions every year — three 20-minute operas and a one-hour opera — and that alone is cause for celebration.

So I went to Friday night’s unveiling of the third round of 20-minute commissions, at the Kennedy Center’s Terrace Theater, with the benignly supportive attitude of a parent attending a school concert, there more for the principle of the thing than for the substance of the performance. And I was happily surprised.

I quite enjoyed the first piece, “The Investment” by John Liberatore and Niloufar Talebi, a vignette of an Iranian couple (Wei Wu was effective as the husband) who buy a painting by an Iranian-born artist (played by the silver-voiced Raquel González), then learn that it seeks to express political sentiments they don’t share.

I sympathetically saw the flaws in the second piece, “An American Man” by Rene Orth and Jason Kim, which tries to compress the complexities of American politics in a scene between an ambitious candidate, his sister (Aleksandra Romano, who sang well both here and in “The Investment”), his aide and the memory of his newly dead father with an “unsavory” past. The result is a little naive and overly talky.

And I was thoroughly amused, as I was meant to be, by “Daughters of the Bloody Duke.” The composer Jake Runestad and the librettist David Johnston responded to the limitations of their prescribed form with a loving sendup that amounted to a 21st-century take on an early-19th-century Gothic ballad (40 daughters marry 40 sons, with the goal of killing every one) expressed in the vocabulary of musical comedy. It seemed to be as much fun for the singers — including Jacqueline Echols weaving across stage as a drunk, knife-wielding sister, Deborah Nansteel as the vengeful ghost of Grandmother, and Kerriann Otaño and Patrick O’Halloran as the straight-man couple at their mercy — as it was for the audience.

Michael Brandenburg and Aleksandra Romano in The Washington National Opera's production of "An American Man." (Scott Suchman/For The Washington National Opera)

WNO, like many other opera houses commissioning new work, appears to be honing its ideas about how to workshop a piece as this program continues to develop. (Anne Manson, the evening’s conductor, is one of the WNO program’s three mentors; the others are Mark Campbell, who works with the librettists, and Jake Heggie, who advises the composers.)

The result is, for better or worse, an ever-slicker product. Programs like this are not seeking true innovation, the kind of wacky potpourri presented by, for instance, the new-work readings at the Vox festival of the late, lamented New York City Opera. Rather, the point of this particular exercise is to learn how to work within the existing framework before you set out to explode it. A 20-minute opera in this mold rides heavily on its libretto; in effect, it’s a long shaggy-dog story with some kind of punchline at the end.

There’s not a lot of time for the music to take hold, although all three composers dealt elegantly with the 13-piece chamber orchestra — the regular strings and winds, plus piano, timpani and percussion — in different ways. Liberatore opened and closed his piece in a kind of mirror-image parentheses: a rumble of timpani and bass leading to a sparkle of xylophone followed by a solo cello at the beginning, the same instruments tying up the package in reverse at the end. Orth offered some nice vocal writing for her tenor, Michael Brandenburg, as the hapless candidate Wyatt.

And Runestad had fun going over the top, piling melody upon melody in a celebration of camp. “Daughters of the Bloody Duke” deserves to have a long and happy life in conservatories and apprentice programs. I would love to see what its creators come up with next.

WNO’s American Opera Initiative next surfaces on Jan. 23 and 24 with the world premiere of the hour-long opera “Penny,” by Douglas Pew and Dara Weinberg, who wrote the 20-minute opera “A Game of Hearts” for the American Opera Initiative in 2012.

Jacqueline Echols, Patrick O'Halloran and Kerriann Otano in The Washington National Opera's production of "Daughters of the Bloody Duke." (Scott Suchman/For The Washington National Opera)