The pleasures of the G&S comic operettas are divided pretty equally between G and S: on the one hand, W.S. Gilbert's intricate, witty rhymes, lyrics and plot, and on the other, Arthur Sullivan's rich melodies and varied interplay of solos, small groups and chorus. There's also the parody and wry commentary that sharpen occasionally into genial satire, which are shared by both words and music, as well as the staging that brings them to life.

But you go to the Pittsburgh Savoyards, faithful tenders of the local G&S flame for 68 seasons, and it's mostly about the music. Under music director/conductor Guy Russo, the Savoyards have a competent amateur orchestra that numbers 20-some, depending on performance, and that makes a persuasive case for Sullivan's enduring appeal. Casting tilts toward the music, too, generally favoring vocal ability over acting.

"The Pirates of Penzance" is one of the G&S favorites, along with "Mikado" and "Pinafore," and so appears regularly every few years. Its mild mockery of Victorian snobbery, pretension and feckless idealism neatly matches Sullivan's parody (and appropriation) of operatic cliche.

John Blankenbehler directs his first Savoyards show. I wish he and choreographer Stephanie Holt Blankenbehler had a larger chorus to work with. The six men sound well enough, but the 12 women are sometimes faint, and those numbers work out to a climactic battle between just five bobbies (including their sergeant) and the same number of pirates.

Showing the most flair are Corey Nile Wingard as the Pirate King and Meighan Lloyd as Ruth -- he with bare-chest, flowing curls and flashing eyes; she with pint-sized swagger and a big voice. Jack Mostow is a capable Major-General, surviving his famous tongue-twisting solo with aplomb. Young Anna McTiernan's Mabel has a pretty but very soft voice, and Andrew Boag does well by Frederic's priggishness.

In general, the smaller roles and chorus are better off when they resist the temptation to act, letting the music carry them along. G&S have been doing that for well more than a century. All the Savoyards need is an audience to share the pleasant results.

"Pirates" runs through March 4 at Catherine Thomas Theater, Benedictine Sisters, 4530 Perrysville Ave., Ross; 8 p.m. Friday and Saturday, 2:30 p.m. Sunday; $6-$15; 412-734-8476.