And now for something not quite completely different: "Da Ali G Show," an HBO comedy series that introduces British comedian Sacha Baron Cohen to American audiences. One problem is that sometimes Cohen seems less interested in attacking funny bones than in appealing to sadistic streaks.

The series premieres at 12:30 tonight after the debut of "Real Time With Bill Maher" -- which is live and therefore unpreviewable -- and immediately sounds a dissonant note. In a flat and poorly directed introductory monologue sprinkled with malapropisms, Cohen says, "There's been enough sadness since the terrible events of 7/11."

Cohen is in character as the clueless Caucasian hip-hop interviewer Ali G, but nothing excuses joking about Sept. 11, 2001. The word "tasteless" doesn't begin to cover it.

It's a tiny detail in the show, though, and over with quickly. Cohen plays not only nitwit hip-hopster Ali G, whose huge yellow slicker looks like a deflated weather balloon, but also Borat Sagdiyev, boorish host of the no-budget cable show "Borat's Guide to America," which is aimed chiefly at Sagdiyev's fellow Kazakhs.

Whatever the guise, Cohen uses real people as props for his comic riffs. They often appear to be unknowing victims, lured into what they think will be a serious interview and then subtly or bluntly ridiculed. For the premiere, Cohen has mysteriously landed former attorney general Richard Thornburgh, who tries to correct G's misperceptions of what a "hung jury" is. G thinks it means well endowed.

On the second show, airing a week from tonight, G puts such questions to former U.N. secretary general Boutros Boutros-Ghali as "Is Disneyland a member of the U.N.?" He also gets Boutros-Ghali to spell the French word for poo-poo. The guest seems delighted.

There is a strangely ingenuous charm to much of what happens, and most interviews end with everybody smiling and Cohen/G expressing his gratitude. Though the premise is anything but unprecedented (with similarities to Stuttering John pranks on the Howard Stern radio show, to Martin Short's self-absorbed celebrity interviewer Jiminy Glick, and many more), Cohen can be funny in fresh and unexpected ways.

But sometimes the spoofing comes off not as good-natured but as mean-spirited. A priest who is part of a panel on religion on next week's show strikes back when Cohen's jokes about Jesus Christ and about nuns become crudely offensive.

As Borat, Cohen shows up at a dinner with members of the conservative Sons of the American Legion and their wives and sits there making snidely smutty dinner-table conversation about porno, prostitutes and flatulence. Is this all in fun, or is Cohen treating his victims with contempt, laughing inside about having tricked them into looking foolish on television?

The amount of sadistic humor now on American TV is flabbergasting. No one would watch Fox's "American Idol" if it dropped the gimmick of featuring untalented people and humiliating them, often to the point of tears. Even commercials are trying to get laughs out of such violent acts as poking a woman's eye out and injuring dogs.

We can hardly blame Cohen for the context, of course, and there are hilarious happenings in his show, as when (next week) he asks Brent Scowcroft whether America should "nuke" Canada just to assert itself, or when as Sagdiyev he asks an etiquette counselor how much one should tip a prostitute. On tonight's show, there's a long sequence of Ali G going through training maneuvers at the Philadelphia Police Academy; at one point it evokes memories of Bud Abbott drilling Lou Costello in "Buck Privates." It has the purity of slapstick clowning.

HBO has scheduled only six episodes of the show at this point, which seems an awfully cautious way to showcase a new young talent. Whether Cohen can become a sensation in six weeks is problematic, but at least his heart's in the right place -- most of the time, anyway, and assuming he really has one.

Sacha Baron Cohen as that wild and crazy Kazakh, Borat Sagdiyev, on HBO's new comedy series. Sacha Baron Cohen, in his Ali G persona, "interviews" Boutros Boutros-Ghali, the former United Nations secretary general. Hilarity, as well as spelling, ensues.