Anticipation for "The Student Prince" was for the something old -- this circa-1924 operetta -- and something new -- tenor Chad Johnson and soprano Jaquelynne Fontaine, in their Pittsburgh CLO debuts.

The draw was to be the youthful, rich voices tackling demanding roles and to see how a deep, deep-roots musical tradition follows "The Producers" and "Hairspray" into the Benedum Center.

I left Tuesday night's opener chuckling and with thoughts lingering on something reliable: CLO veteran Tim Hartman and his partner in comedic scene-stealing, Patrick Richwood. The latter, an accomplished screen actor (he was the elevator operator in "Pretty Woman"), was the perfect physical foil to the oh-so-tall Mr. Hartman's supercilious Lutz, the king's valet. The relatively short Mr. Richwood was Hubert, put-upon valet to Lutz.

The main event of "Prince" may be the forbidden love of a king and a peasant and their "we'll always have Heidelberg" relationship, but their cohorts made the comedy shine. Mr. Hartman/Mr. Richwood had so much fun in their overlord-servant relationship, we'll excuse any moments that went beyond over the top.

"The Student Prince" has been played countless times before here and elsewhere as it rolls toward a century in production, but there's a reason it was last on Broadway in 1943 and last made a big-scale splash in 1954, when Mario Lanza's voice was part of the soundtrack for the MGM big-screen version.

It's this CLO season's major throwback and your enjoyment of it depends heavily on whether you can make the leap backward from the rock 'n' roll frolic "Hairspray" that just left the building.

Ms. Fontaine's crystal-clear soprano and effortless acting made her a treat as Kathie, the barmaid and object of the prince's affections. Mr. Johnson grew into his role from stiff-backed innocent prince to student lover, then to second-act heartbreak as the dutiful king. They were aided by Ed Dixon, poignant as the prince's playful and faithful teacher, Dr. Engel.

The second-act "Montage," in which the newly crowned king can't get Heidelberg out of his head, gives Mr. Johnson a chance to shine as he struggles with his forced engagement to a princess -- royalty must marry royalty, after all. He paces and sings in front of a backdrop that goes from opaque to transparent, allowing him to hear (and us to see) the people still deep in his heart: Dr. Engel, his stalwart student friends and Kathie.

The standard of good times in Heidelberg, where Karl Franz escapes the stifled life of the palace for a student's life, is "The Drinking Song." The chorus of 15 strong male voices makes it a rousing call to "drink, drink, drink" and, by inference, misbehave.

That's the one song that may stick in your head as you walk up the aisles, but I was still musing over the exploits of the Hartman/Richwood duo. The passion of the prince and the peasant were no match for Mr. Hartman's comeuppance and Mr. Richwood's triumph, with his Wilfred Hyde-White voice lingering in the Heidelberg air.

Credit their comedic timing and a couple of other reliable sources of slapstick with providing welcome laughs: Myrna Paris as the ambitious future mother-in-law to the heir to the throne, and Madeleine Doherty, fresh from the CLO's "The Producers" and "Hairspray," as the bawdy barmaid Gretchen. Stuart Marland, who also has followed through on several CLO shows this season, lends stalwart support as the prime minister of fictional Karlsburg.

Local theater-goers will recognize other regulars from Pittsburgh's musical theater scene, such as Gene A. Saraceni (Old Josef) and Peter Matthew Smith (Captain Tarnitz). Newcomer Shana Farr is lovely as Princess Margaret, the distant cousin who must marry the prince while knowing he loves another.

Even if that makes your mind wander to a modern-day Princess Di reference, "The Student Prince" may seem creaky in story and tone for the 21st century. Again, depending on your musical-theater preferences, you might say the same for the only new show of the CLO season, the charming but old-fashioned Kander-Ebb whodunit, "Curtains."

With "Prince," there's a long history of appreciation. Sigmund Romberg's operetta was the longest-running musical of the 1920s, touring almost constantly.

As the CLO season-ender, the show fulfills big chunks of the company's mission, to stretch boundaries for its talented young ensemble members and to preserve the American musical theater art form.

Brisk direction by James Brennan elevates the production, which runs about 90 minutes with intermission.

And Tim Hartman and Patrick Richwood demonstrate that pratfalls and just plain silliness can be timeless.

CLO Ensemble Award

Pittsburgh CLO's annual Julia Deberson Award for outstanding ensemble member has been granted to Ahmad Simmons, a Texas native who has been completing his studies at Point Park University while appearing in a dozen CLO shows. The recipient is chosen by the season's directors and production staff for his or her skill, work ethic, attitude and passion for working in musical theater.