Reprinted from yesterday's late editions.

Giacomo Puccini made a real mistake when he lavished his mature musical powers on setting David Belasco's often banal horse opera, "The Girl of the Golden West." But lavish them he did, as the New York City Opera's audience Thursday at the Kennedy Center was lucky enough to experience.

It's hard to believe that an extended work on an American theme by one of the most protean creators of fine vocal music is almost never performed, in this country or almost anywhere else. After all, "Trovatore" is pretty silly dramatically, but that doesn't keep it off the stage.

But until you've seen "The Girl" you don't know how much silliness can mess up an opera, regardless of the quality of the score, and this score is a beauty.

Belasco's work deserves the characterization "horse opera," and no better. This is Hopalong Cassidy-level theater - not remotely up to the equality of "Gunsmoke" - even though the soprano lead does have a superficial resemblace to Miss Kitty.

The performance was splendid. Soprano Marilyn Zschau, with her soaring high tones, and sweet-voiced tenor Jacque Trussel, are new with the company. They show real promise. Showing more than promise was the conductor, Baltimore's Sergiu Commissiona, who demonstrated his customary flair for the visceral element in music.

Frank Corsaro's production, also, does the best it can for Puccini. Furthermore, the City Opera should be thanked for giving us the opera. They did their best, and they could not have been expected to solve the central dilemma - that "The Girl" is not worth staging and is very much worth performing. The opera is repeated Sunday.