The Grand Duke is generally regarded as the worst of the Gilbert and Sullivan operettas. But, really, it isn't that bad. Yes, the plot is ridiculous, but that is actually true of all of the operettas. (Okay, the sausage roll thing is unforgivably absurd, but is it really that much sillier than all the switched at birth plot lines?) Its greatest flaw is really that it just isn't as brilliant as, say, H.M.S. Pinafore. Sullivan's score is pleasant enough (I walked out humming "The Prince of Monte Carlo") and there are plenty of laughs, including Gilbert's self-referential line about rhyming lyrics (When exigence of rhyme compels /Orthography forgoes her spells,/ And "ghost" is written "ghoest") and the Athenian court dress (costumes from Troilus and Cressida) at the beginning of the second act.
As for the performances, I was quite impressed with Guillaume Tourniaire as Ludwig and Alexandra Boule-Buckley as Julia. Both were expressive actors, as well as having strong voices. John Perine as Rudolph and Ann Coffman as Lisa were also up to the challenges. Unfortunately, Rick DuPuy was a less than energetic Ernest and had a lot of trouble projecting his voice. He was a good argument for having supertitles for an operetta in English. Blair Eig was also somewhat weak as the Prince of Monte Carlo. Still, for an amateur company, the performance standard was better than average. I was also impressed by there being a full orchestra. Signature Theatre did Sweeney Todd with just 4 musicians, so having 32 for this is quite an achievement.
All in all, it was an entertaining evening which raised my opinion of this minor Gilbert and Sullivan work.