The variety show is dead. The variety show is the biggest thing on television.

Stop: You’re both right!

Musical-comedy variety shows of the Carol Burnett/Sonny and Cher/Lawrence Welk school have certainly vanished, and efforts to revive them have met with grim results. Remember those Nick and Jessica specials?

But one can’t look at shows like “American Idol” and “Dancing with the Stars” and not see them as variety shows in disguise, complete with singing, dancing and sporadic efforts at comedy.

So it’s nice to see NBC host a variety show of the old-fashioned kind, “Tony Bennett: An American Classic” (7 p.m., NBC), a celebration of the singer’s 80th birthday and a showcase of duets between Bennett and artists including Barbra Streisand, Elton John, Stevie Wonder, Diana Krall and many more.

At one point, the cinematography returns to black and white, the NBC logo returns to a graphic not seen in 40 years and the set looks like something left over from “The Judy Garland Show” circa 1962. Out comes a company of dancers to perform to a medley of Bennett classics and set up a number between the birthday boy and Krall.

Viewers of a certain age may be transported to variety shows of old. Younger viewers may find it reminiscent as well. The buoyant choreography has all the feel of one of those commercials for the Gap, or, more to the point, Target. And that’s just the point. Because the real name for this special hour of music is “Target Presents ‘Tony Bennett: An American Classic.”‘

¢ In other musical news, Jimmy Kimmel hosts the 2006 American Music Awards (7 p.m., ABC), a celebration of the year’s best, or at least the best-selling.

Performers include the Dixie Chicks, the Pussycat Dolls, Nelly Furtado and Mary J. Blige.

¢ The “Frontline” (8 p.m., PBS, check local listings) presentation “Living Old” offers a sobering look at America’s demographic destiny. People 85 and older make up the fastest-growing segment of the U.S. population.

Over the past decades, better medicine, sanitation, healthier lifestyles and other factors have enabled people to avoid the communicable and chronic diseases that would have killed them in their 50s, 60s and 70s. Now, many people face extreme old age and a loss of mobility and function at a time when society is ill prepared to care for them.

¢ The two-hour special “To Love and Cry in L.A.: Why Stars Split” (9 p.m., E!) looks at Tinsel Town breakups and divorces.

Tonight’s other highlights

¢ Lorelai breaks the big news to Rory on “Gilmore Girls” (7 p.m., CW).

¢ A young patient faces some crucial questions about his family history on “House” (8 p.m., Fox).

¢ A college trustee (Patricia Hearst) is kidnapped on “Veronica Mars” (8 p.m., CW).

¢ An expectant mother worries that a cancer treatment may hurt her unborn baby on “3 lbs.” (9 p.m., CBS).