Eric Teague’s sketch of the lion costume for the Washington National Opera’s "The Lion, the Unicorn and Me." (Erik Teague)

When I was a child, I scorned children’s operas. I looked down on people who went to them. I had attended a few operas, and I felt I was ready for the big stuff. I therefore disdained Humperdinck’s “Hansel and Gretel,” and listened earnestly to my Callas recording of “The Barber of Seville.” I didn’t realize for years and years that of the two, “Hansel and Gretel” is far more musically sophisticated.

This weekend, the Washington National Opera is offering the world premiere of another new children’s opera. “The Lion, the Unicorn and Me,” with music by Jeanine Tesori, is based on Jeanette Winterson’s children’s book about the Nativity, told from the perspective of the donkey (runs through Dec. 22). The work is a continuation of WNO’s new plan, under Francesca Zambello, to present a holiday opera for families every year; last year, we got “Hansel and Gretel.”

WNO is hardly the only company on this particular bandwagon; the Metropolitan Opera has been offering abridged productions of old favorites, including last season’s “The Barber of Seville”; this year, it’s bringing back Julie Taymor’s colorful, pageant-like, puppet-heavy production of Mozart’s “The Magic Flute.”

And there are dozens of children’s operas being written and performed all the time. Opera America’s list of youth opera has literally hundreds of titles, including the obligatory settings of favorite books (three of “Wind in the Willows,” three of “Pinocchio”), though it includes some titles that were not necessarily conceived for children, like Scott Joplin’s “Treemonisha.” I still tend to look askance at some of these efforts.

I’m all for small-scale opera, which increasingly appears to be a way to move the genre into the 21st century by allowing new work to be produced affordably and composers to try their hand at writing it, and children’s opera is one major arm of chamber opera. My reservations, however, are the same as they were when I was a child: the “hey, kids, ain’t opera grand” tone of some children’s productions. Much opera is timeless and ageless, and the operas I attended as a child — “Barber,” “The Merry Widow,” “Die Fledermaus,” “Don Pasquale” — still seem to me reasonable children’s fare.

Children’s opera is hardly new. You could trace it all the way back to the marionette operas of the 18th century. The genre saw a heyday in the 1950s, arguably starting with the 1951 premiere of Gian Carlo Menotti’s “Amahl and the Night Visitors,” the first opera ever commissioned by a television network (“Sound of Music” producers, are you listening?). “Amahl” became a near-instant classic, and spurred other NBC commissions, not all for children and none as successful, though one of them, Lukas Foss’s “Griffelkin” (1955), is being revived by the Minnesota Opera in January. Meanwhile, Benjamin Britten was writing small-scale pieces for and with children, most famously “Noye’s Fludde” (1957), an opera in which I made my stage debut in a school production at the age of 8, playing an alligator.

That I grew up to make a life in music is not entirely beside the point. Singing in “Noye’s Fludde,” or seeing “Amahl” at an impressionable age, can, indeed, help awaken an interest in the genre. The problem lies in the motivation. If you, an artist, have a vision for an opera for children, well and good. If you as a company decide that children’s opera is A Good Thing, and will lead to children growing up to attend more opera, and commission an opera accordingly, it will likely be dead in the water. Opera is already an artificial, problematic genre, as well as a thrilling one; it is not served well by becoming prescriptive. As for “children’s opera” succeeding: I’d maintain that “Hansel and Gretel” has prevailed not because it is a children’s opera, but in spite of it.

And some of the more successful recent “family operas” succeed because they appeal to an adult’s vision of childhood, and nostalgia, rather than a child’s. Mark Adamo’s “Little Women” is a case in point: premiered in 1998 by the Houston Opera Studio, it was brought back to the main stage, and has traveled around the world in literally dozens of different productions, in addition to a PBS broadcast. Written for relatively small forces and a lot of female voices, it’s ideal music-conservatory/training-program fare. When I attended a production at New York City Opera some years ago, the matinee audience was filled with mothers and daughters primed to see a beloved book onstage. Partway through the first scene, Marmee, the mother, appears and says something along the lines of “Come, girls!” A small voice in the seat behind me piped up, incredulously, “THOSE are the GIRLS?”

The moment has stuck with me as an emblem of the challenge of children’s opera: The target audience may go once to an operatic version of “Little Women” or “The Little Prince” (set by Rachel Portman in 2003) or “Babar,” but does the piece offer anything that they will actually connect with, or that will make them want to go back? My son, aged 2, seized on a CD of “Goodnight Moon,” as set by the composer Glen Roven, with delighted cries of “Night-night moon!” but the CD itself left him cold, though perhaps it is up to me to continue playing it for him assiduously until he makes the connection.

I don’t mean to disparage music for children. Many wonderful pieces have been written for children — from “Peter and the Wolf” to Michael Daugherty’s and Anne Carson’s fine “Troyjam,” which the National Symphony Orchestra premiered in 2008. But the latter reinforced my basic bias about this music: I see nothing about it that inherently makes it more for children than adults. “The Magic Flute,” or Ravel’s “L’Enfant et les sortileges,” are two fairy tales that are also among the greatest operas in the canon. I applaud WNO’s efforts to commission new work, and I hope that Tesori’s opera is wonderful. If it is, then a lot of adults will like it.

The Lion, the Unicorn and Me

by Jeanine Tesori with libretto by J.D. “Sandy” McClatchy and presented by Washington National Opera, runs through Dec. 22 at the Kennedy Center’s Terrace Theater. 202-467-4600.