Wacky as its plot is, Verdi’s Un giorno di regno (“King for a Day”) does seem to contain a grain of actual historical truth. Apparently in 1733 King Stanislaus of Poland, exiled to France, asked someone to impersonate him while he snuck back to Warsaw to reclaim his throne. This 1840 comic opera imagines what the impersonator, Belfiore, might have gotten up to while in disguise—arranging the marriage of two couples, one member of which is his mistress. Will Belfiore reveal his identity and betray the real king, or will he stand by as the woman he loves weds someone else? The notorious failure of Un giorno‘s opening night basically put Verdi off comic opera for a half-century (until his final masterpiece, Falstaff ). What was the problem? Probably not the music: The young composer’s bumptious, oom-pah style, which can raise unintentional laughter in his tragedies, raises intentional ones here. (Hearing the overture for the first time, I literally giggled.) More likely it was the scrappy, miscast performance—a problem we won’t have this weekend as Seattle Opera’s Young Artists Program presents the opera for one night only. If anyone can convince us its obscurity is undeserved, it’d be these promising, energetic young singers.