That Irving Berlin -- can he ever write a song! Let's get him to do a new musical! Oh . . . right. Well, let's use one of his old ones, then!

Not a bad idea, on the face of it. Great songs, beloved by millions, with a cheery holiday backdrop and a plot that may be silly but pretty much stays out of the way -- sure, ''White Christmas" could make the transition from screen to stage, couldn't it?

It could, probably, and there are moments in the production that opened last night at the Wang Theatre when it does. It has some terrific dancing (despite too much bland, clumpy choreography), a few truly beautiful moments of singing, and plenty of technical razzmatazz -- up to and including snow. You will, of course, leave the theater humming one of Berlin's irresistibly hummable tunes. But you may also find yourself dreaming of the original ''White Christmas," and wondering why this one feels colder.

If anything, you'd expect live theater to provide a warmth that you wouldn't find in a '50s Hollywood product, which had its birth as a brazen marketing ploy for the hit song that had already appeared onscreen in ''Holiday Inn." But the 1954 movie somehow transcended its commercial roots to generate a genuine charm. Credit the chemistry among the four leads -- Bing Crosby, Danny Kaye, Rosemary Clooney, and Vera-Ellen -- or the ability of that era, now apparently lost, to imbue schmaltz with real feeling. Whatever it was, it worked.

Here, there's not much chemistry, though Stephen Bogardus as Bob (Bing) and Michael Gruber as Phil (Danny) work manfully to show us how much fun they're having together. Kerry O'Malley, in the Clooney role as one of the singing sisters the boys fall for while putting on a show in their former general's Vermont inn, generates the most excitement with a magnificent, warm voice and a strong presence. Nadine Isenegger rounds out the quartet with lively dancing. But none of the four really makes an emotional connection with the material or with each other.

In part that's because, in attempting to make the show more ''logical" than the movie, the book by David Ives and Paul Blake makes a hash of things. No one could argue that the movie was a brilliant piece of writing, and some parts were downright offensive -- the ''Minstrel Number" was wisely cut from this version -- but at least the songs flowed believably out of the characters and the situations. Now, ''Blue Skies" comes -- well, out of the blue. Sure, it's a boffo first-act curtain, but what is it doing in this show?

And why, why, why would you take a sweet and lovely duet like ''Count Your Blessings," which allows Bob to express his dawning love for Betty, and make him sing it to the general's granddaughter while Betty watches him, unseen? Not to mention that the granddaughter, who in the movie barely registers as a (teenaged) character, here becomes an excessively talkative, excessively cute little girl. That's no fault of the child playing her but rather a misjudgment by the writers. There are enough '50s movies with precocious brats; why throw one into a plot that never had one? Maybe to hang out with the housekeeper, now inexplicably transformed into a former Broadway belter with predictable longings.

There's nothing wrong with changing a show if the changes make it better. Ironing out some of the plot twists, for example, does no real harm. But if the Wang keeps presenting this show in alternate years (it hopes to; next year it goes to St. Paul, Minn., whose Ordway Center is coproducing), it would make sense to take another hard look. Lose the cutesies, tone down those lurid green suits, and remember what people really want from ''White Christmas": Let it snow.