Consider Finian’s Rainbow a much-needed palate cleanser. After all the Sturm und Drang this season has already seen (Hamlet, After Miss Julie, A Steady Rain, Memphis), it’s a relief to settle into a seat at the St. James Theatre for an evening spent with a stellar example of the Golden Age of musical comedy.

That Golden Age might not be for everyone, of course. The sedate pace of Finian’s Rainbow (which premiered in 1947) may be lethal for some audience members’ patience, and the whimsical plot—a satire on race and economics that features a leprechaun, sharecroppers and a pot of gold—may simply be unavoidably twee and old-fashioned for some. But for anyone with an open mind regarding cultural artifacts from a vastly different time, it’s hard to not be won over by the strong performances, inventive staging, and a gorgeous, rarely heard score. Sure, songwriters Burton Lane and Yip Harburg wrote “Old Devil Moon” and “How Are Things in Glocca Morra?” for the show, but how many casual ticket buyers will know “Necessity” or “When the Idle Poor Become the Idle Rich,” two superlative comedy numbers that get the deluxe treatment from director Warren Carlyle and his stellar cast?

The problems with the show turn out to be not the long-feared transformation of a bigoted Southern Senator into an African American (that pot of gold is to blame), but the structure of the show. The first half of Act One suffers from a succession solo songs, while the second sags under the weight of two big group numbers in a row. And Carlyle has found a clever way to transform that senator without making the plot device feel in any way racist.

But who cares if the placement of the show’s songs can feel repetitive when we have the chance to see Cheyenne Jackson prove once and for all that he’s more than just a gorgeous face and a pin-up body, comfortable only in campy musicals like Xanadu and All Shook Up? He’s giving a leading man performance as sharecropper Woody, and he’s entirely at ease with sincerity. Perhaps a little too at ease, since he frequently smirks and mugs in character while relegated to the background of other actors’ songs. But Woody is, in many ways, an overgrown boy who finally reaches maturity thanks to recent Irish immigrant Sharon. And one of the highlights of the show is the chance to see and hear Kate Baldwin’s Sharon turn him into a man, while wrapping her rich, warm voice around Sharon’s songs—even the pun-heavy “Something Sort of Grandish.”

Still, even the show’s weaker songs have a certain archival charm. Every now and then, it’s nice to be reminded that not all musicals have to be as ambitious as Next to Normal, and that not all Golden Age shows are as lacerating as Gypsy. Sometimes, musicals can just be accomplished bits of lightweight entertainment, an ambition that has been sorely missed lately.

> Finian’s Rainbow

Open run, St. James Theatre, 246 W. 44th St. (betw. Broadway & 8th Ave.), 212-239-6200; times vary, $25-$120.