In case you needed a reminder of how passion and dedication can see an organization through its ups and downs, the Comic Opera Guild is now celebrating its 40th anniversary, with a production of Franz Von Suppe’s 19th century Viennese operetta “Light Calvary”—never before staged in the U.S.—and an anniversary luncheon at Weber’s Inn.

As with many of the shows that COG has staged over the past 40 years, the company had to do some super-sleuthing to unearth orchestrations, and a basic synopsis, for “Light Cavalry,” and co-founder Tom Petiet worked hard to “re-create” the otherwise lost-to-time show, providing lyrics and dialogue.

“It’s a challenge, but having done 112 shows, we’re used to the format now,” said Petiet. “We’ve studied these shows, and we know how to put them together. We don’t try to update them. …

"They’re done in the style they originally would have been done in, but in a way that’s accessible to a modern, English-speaking audience. So we don’t try to translate the show word for word. … It’s as if a composer gave us the score, and we say, ‘OK, we’re going to do a show around this.’ So it’s really like creating a new show.”

Petiet began his journey with COG after graduating from the University of Michigan, where he had been heavily involved with the U-M Gilbert and Sullivan Society.

“I wasn’t familiar with the rest of the operetta genre, other than Gilbert and Sullivan, so I thought, ‘I wonder what else is out there,’” said Petiet. “(UMGASS members) weren’t interested in anything but Gilbert and Sullivan, but I still wanted to see if these old show could be brought to life again. … I thought this was a need and an opportunity, so we created Comic Opera Guild.”

A handful of performers Petiet got to know through UMGASS—including his wife, Patricia—thus planned an inaugural double bill production (Mozart’s “Bastien and Bastienne” and Gilbert and Clay’s “Age Ago”), which premiered in January 1974 at U-M’s Trueblood Theatre, in the now-demolished Frieze Building.

“We’d decided to pursue our dream, but it didn’t start very well,” said Petiet. “The first thing we did lost a thousand dollars. In 1974, that was a lot of money—mostly my money. … The problem was a problem we’ve had throughout our history. Because we’re doing things that no one else does—people don’t come to see things they’ve never heard of.”

COG looked stillborn; but fate intervened with an opportunity to present a dinner theater show in the Huron Hotel in Ypsilanti. Petiet, Gersh Morningstar and Ron Orenstein performed Sullivan’s farcical one-act “Cox and Box,” and it had a run of 22 performances while also making up for the previous production’s losses.

When New York City opera star Eva Likova came to teach at the University of Michigan, COG launched preparations for its most ambitious production by far: Johann Strauss’ “Die Fledermaus” at Lydia Mendelssohn Theater.

But the final dress rehearsal for the show was, well, less-than-promising.

“Lots of the principals didn’t have their lines down pat,” said Petiet. “The rehearsal was just a disaster. An absolute debacle. … I think we were all just thinking that we’d go out on stage and embarrass ourselves. But somehow we got it together for the opening performance. And I remember the backstage pandemonium after - it’s something I’ll never forget, because the whole thing was looking so bad, and it came out so well. That was the show that really launched the group. We knew then that we could continue to do this. “

And continue they did. Over four decades, COG has worked with more than one thousand singers, musicians, crew members and business staff while reviving rare comic operas and operettas by Strauss, Offenbach, Lehar and Romberg, as well as early American operettas by Victor Herbert and Jerome Kern. Plus, about a decade ago, COG began to offer cast recordings of their shows, and having these scores (sometimes never previously available) for sale online, to operetta fans all over the world, has been a key factor in keeping COG financially afloat.

Finally, COG has also, since 2000, worked to discover vocal talent by way of vocal competitions, awarding more than $40,000 over the years. And the group’s professional vocalists aren’t always necessarily from the Ann Arbor area; they also hail from St. Clair Shores, Brighton, Pinckney, and Jackson.

“We’re an organization for singers—classical singers,” said Petiet. “ … We’re promoting not just material but performers as well.”

To celebrate COG’s 40th anniversary, the company will host a luncheon at Weber’s Innduring which current performers, alums and fans may watch video clips from past productions, hear remembrances, and participate in a sing-along—on the heels of COG’s musical-in-concert presentation of “Light Cavalry,” which focuses on Wilma, a beautiful young girl who, after being found wandering as a child, has been treated as a cleaning wench by the Mayor and his wife, and kept from her lover, Hermann. When a troop of Hussars come to town, Wilma discovers that she’s the lost daughter of the Colonel, who makes it his business to deliver comeuppance.

Known only for its overture, featured in pops concerts, commercials and movies, “Light Cavalry” became a point of curiosity for Petiet as a child, who wondered what happened to the accompanying show.

“Now we’re in the thick of rehearsals for it, and we’re all looking at each other and saying, ‘I cant understand why this show was buried for so many years,’” said Petiet. “The original book must not have been all that good. … You’ve got to have the combination (of good music and a good libretto). If you don’t have both, it’s not going to stick around.”

So is Petiet looking toward a 50th anniversary for COG?

“That would be on the end of the bucket list,” said Petiet. “To go to 50—that would be something.”

Jenn McKee is the entertainment digital journalist for AnnArbor.com. Reach her at jennmckee@annarbor.com or 734-623-2546, and follow her on Twitter @jennmckee.