Who wrote the song "How Do You Do It, Mabel, on Twenty Dollars a Week?" Clue: He also wrote "White Christmas." And "God Bless America." And "Blue Skies." And "There's No Business Like Show Business." And "A Pretty Girl Is Like a Melody." And "Easter Parade."

Now you know. You probably knew five titles ago.

Irving Berlin, who managed to live through about nine-tenths of our rapidly expiring century (he died in 1989 at 101), perhaps wrote more good songs--both the music and the lyrics--than anybody else, ever. He could have hung a sign outside his door that said, "Hits for All Occasions," because eventually he seemed to cover every holiday, human emotion and state of mind.

There were sad songs, like "All Alone," but most were joyous. Thus it's especially unfortunate that the A&E cable network has come up with a "Biography" of Berlin--"Irving Berlin: An American Song"--that practically defines joylessness. The two-hour special premieres tomorrow night at 8.

At least the show reveals its true colors right off the bat. It opens in 1925 when, according to the documentary, Irving Berlin's love life was the talk of the town. He planned to marry Ellin Mackay; she was Catholic and from a snooty family, he was Jewish and the son of Russian immigrants. New York was all aflutter.

From the prominence it gets in the program, you'd think this was the key moment in Irving Berlin's life. The "tabloids" of the time are tsk-tsk'd for dwelling on Berlin's affair and blowing it out of proportion--but that's exactly what this "Biography" does. Exactly! There's no reason to begin in 1925 except to try to grab a viewer's attention with a smidgen of scandal upfront.

The show never recovers from this ugly blunder. It is amazingly blah. Another major problem is the narrator, Harry Smith. A nice man and an able journalist, Smith is no good as a narrator. His flat, bland voice never conveys drama, poignancy, irony, emotion of any kind. He might as well be delivering a graduate thesis in biochemistry, the big drip.

Of course there are plenty of celebrities that A&E could have hired to narrate the program--people associated with Irving Berlin and his music. But that would cost money; Smith is on staff. A&E is very, very cheap. They're as cheap as Scrooge himself. That may be why this documentary about the most American of all American songwriters features shockingly few of his American songs.

That's right, it's a musical biography without much music.

What the show does have is a gallery of estimable experts who speak about Berlin--chiefly the composer's unimpeachably authoritative daughters, Linda Emmet, Elizabeth Peters and Mary Ellin Barrett. They talk with warmth and affection about Our Dad, the Genius.

Also participating is Bobby Short, the greatest cabaret artist in the world; Bernadette Peters, now starring in a hit revival of Berlin's "Annie Get Your Gun" on Broadway, and fun couple Helen Gurley Brown and her husband, David, who recall trout-fishing at Berlin's country estate, where Berlin made sure the pond was always overstocked with trout. When these people talk, the show comes to life.

The script, though, is hardly brimming with insights. Says narrator Smith: "At heart, he was a songwriter, happiest when he was at his piano." Duhhhh, no kidding! The producers apparently didn't want to shell out much money for film clips. Though a number of Hollywood movies were made with all-Berlin scores, we see only a fleeting snippet or two.

For some odd reason, some scenes included from the Technicolor film "This Is the Army" are in black-and-white. Berlin himself sang his great lament "Oh, How I Hate to Get Up in the Morning" in that film, but little of that is included. Now for years, "This Is the Army" was in the public domain and area public TV stations would air tattered, bleary prints of it. Then a restored, authorized version appeared on one of the all-movie cable channels. One would think A&E would have access to this version.

It should be noted in fairness to A&E that in his last 20 years or so, Irving Berlin the elfin sweetie pie became Irving Berlin the elfin curmudgeon. Since he had set up his own publication company, he truly owned almost all of his songs, and he became churlish and cranky about letting people sing them or use them in movies. There are no Berlin songs in the first "That's Entertainment!" because he was wary of the project. By the time the sequel came out, he'd been cajoled into permitting a few Berlin numbers.

Anyway, you'd think that if A&E's producers could get access to Irving Berlin's daughters, they could also have obtained access to more of his songs. The visual illustration in the show is paltry, with heavy reliance on old still photographs that aren't very good in the first place.

At least, though, for all the show's glaring deficiencies, attention is being paid to Irving Berlin. Think about it: Every week, hours and hours of cable programming are devoted to rock stars and baby-boomer icons, as if American music didn't begin until the first twitch of an Elvis hip. It truly is getting to be rock around the clock on cable TV. VH-1 profiles a rock star every night, and the pattern is always that they hit it big, fell upon hard times, reinvented themselves and then returned. Big deal.

What a pity if legacies like Berlin's were allowed to fade away while we all sit around and remember Hootie & the Blowfish.

Even Berlin's death is handled rather matter-of-factly in the documentary, when in fact this time it truly could be said that an era had ended. Not long after Berlin died, singer Short wrote an appreciation for the New York Times that ended cleverly and touchingly with a paraphrase of the lyrics to "Alexander's Ragtime Band." Berlin had his detractors, Short wrote, but to most people he would be remembered as "just the bestest man what am."

He certainly deserves a "Biography" much bester than the one he gets.