By Thomas Garvey

It hit me about halfway through the second act, when a shirtless Joe Wilson, Jr. slid down a rope and began to work a truly spectacular set of pecs: “Ain’t Misbehavin’” could be the horniest show I’ve ever seen in Boston.

And Wilson is the horniest thing in it – in fact, his torso alone trumps the combined naughty bits of the entire cast of “The Full Monty.” Letting one suspender slo-o-wly slide off his shoulder, Wilson teases the audience with a frank, sweaty (and I mean really sweaty) sexuality that probably hasn’t been seen in this provincial burg since the golden age of burlesque.

Which of course wasn’t far from the milieu of Fats Waller, the bawdy source of this evergreen revue. A genius at “stride piano,” a jazz/rag amalgam in which the bass line all but bounces over the keyboard, the classically-trained Waller wrote and sang of low pleasures with a hearty, honest passion (and just a trace of rue) that seems utterly lost to us today – and which at first seems lost at the North Shore Music Theatre, too, where the current revival is running until June 18th. It’s not that veteran director Kent Gash doesn’t understand the material (he knows his way around every double entendre, and in general shapes the staging well), or that the cast doesn’t have the chops to put it over (they do, and then some – as does the terrific pit band, led by the imperturbable pianist Darryl Ivey, who faces down fingerings that would have given Horowitz pause). It’s simply that the North Shore’s vast arena stage initially feels like a refrigerator in which Waller’s candle can only flicker (while the all-white audience looks on with earnest sympathy).

But if you’d bet on that refrigerator rather than that candle, you’d have bet wrong. Slowly the temperature does rise, buoyed both by Waller’s genius and the indefatigable energy of the tight five-person cast, who overcome both the North Shore’s setting and its tendency toward over-amplification (what, can’t this crowd turn up their hearing aids?) to find the happy (if broken) heart of this fierce little show. There’s no plot, and in fact little in the way of the spoken word at all, but then how many musicals can boast the likes of “T’Ain’t Nobody’s Bizness If I Do,” “Honeysuckle Rose,” “The Joint is Jumpin’,” and “I’m Gonna Sit Right Down and Write Myself a Letter,” not to mention the title tune? Simply put, “Ain’t Misbehavin’” is a pure shot of musical pleasure delivered with a chaser of attitude, and if that’s not enough for you, maybe you should check your pulse.

Of the talented cast, Wilson was certainly the standout, although his voice was not as strong as his electric presence and sizzling dance moves (that shirtless number, “The Viper Drag,” in which he all but makes love to an imaginary “five-foot-long reefer,” is one for the history books). Meanwhile, Idara Victor, whom Wilson often partnered, actually had both pipes to die for and a shimmying physical command that could quickly slide from hot to hilarious. (It was no surprise to see these two had both done the show before – probably the rest of the cast will soon match their onstage ease and intimacy.) Of the newcomers to the revue, NaTasha Yvette Williams, while perhaps not entirely erasing the memory of the late Nell Carter (who became a star in the original staging) still found her own sweet, bumptious take on such saucy numbers as “Find Out What They Like,” in which she was ably abetted by the almost-too-sparkling Monique L. Midgette, who was actually at her best when she simply held still for the softly sung, heartbreaking “Mean to Me.” Rounding out the cast was the versatile Ken Robinson, who soared through such lightly satirical numbers as “Lounging at the Waldorf,” but who hadn’t yet found the hilarious heart of the bluntly honest “Your Feet’s Too Big.”

So “Ain’t Misbehavin’” ain’t quite perfect, I’m afraid – the show gets hot, all right, but it never quite achieves the intimacy that the best versions do. And the revue itself is sometimes less than adroit in its pacing (particularly in the swing between the broader-than-broad “Fat and Greasy” and the suddenly-grim, if beautifully staged, “Black and Blue”). But it’s still as close to hog heaven as I think we’re going to get in this world.