The newly expanded judge panel. Courtesy of Fox.

Television years are much like dog years. With each year that passes, television shows age exponentially. Their narratives peter out and their production staffs try everything in the book--stunt casting, shocking deaths, changes of locale--to energize them. This law of diminishing returns extends beyond scripted television, though. Unscripted shows also have to constantly find new ways to shake up the formula in order to stay relevant.

It comes as no surprise, then, that the producers of "American Idol" are unveiling in tonight's season premiere--the show's eighth--a new, fourth, judge, songwriter Kara DioGuardi . She'll join Randy Jackson, Paula Abdul and Simon Cowell, the judges who have lorded over the singing competition since it began in 2002. The caustic Cowell will have a tiebreaking vote during the audition rounds.

As cast shakeups go, it's not a bad choice. "Pop Idol," the British show on which the American version is based, has always had four judges. In its second season, the producers of the U.S. show tried to add radio personality Angie Martinez, but she quit early on. DioGuardi, meanwhile, is a respected songwriter, and at 37 she brings a fresh approach to the judging of a show that frequently uses the youth and youthfulness of its contestants as a basis of criticism (average age of the other three current judges: 49).

But if the intent is to stop the show's audience attrition--it dropped 7% in total viewership last season over the year before--DioGuardi's addition isn't going to cut it. In order for "Idol" to survive, it'll have to stop thinking of itself as a talent competition and start thinking of itself as what it has always been: a reality competition show.

"Idol" producers have always seemed to pride themselves on the purity of their competition, a democratic system in which the nation's best undiscovered singing talent is crowned. But with "Idol," just like any democracy, when people don't agree with the result, they become disillusioned. It started as early as season 2, when Ruben Studdard eked out a victory over Clay Aiken, inspiring thousands of Aiken's fans to complain to the FCC about possible fraud and vote tampering. And in many seasons, there has been a superior talent (see: Chris Daughtry, Melinda Doolittle, Elliott Yamin) who is cut down too soon due to the unpredictable ebbs and flows of voter's habits, or just their tin ears.

When oddball soul singer Taylor Hicks clenched the title in the fifth season, even the show's producers acknowledged that the viewership had made a terrible mistake. And the following season gave rise to Sanjaya Malakar, the tuneless teen who captured the nation by sailing through week after week despite an apparent talent deficiency. The image of "Idol" as a pure meritocracy was shattered ages ago.

The show's producers seem not to have noticed. "There were no panic changes," said exec producer Ken Warwick on a conference call. "It wasn't, `Oh, my God, we've dropped 7 percent. What are we going to do to change the whole show?' This wouldn't have been on TV for eight years if it wasn't doing it right." After eight years, almost any show is wobbling and in need of reinvention, and so far "Idol" has only made minor changes to the competition. Last season, they created a rule that contestants could play an instrument during their performances, a move to enhance the show while showcasing the musicianship of its contestants. It accomplished the latter goal, but not the former. DioGuardi will probably give the show a temporary bounce, as curious viewers tune in to see where her comments will fit in between Jackson's complaints about "pitchiness" and Abdul's sartorial compliments. But the only thing that will really rescue the show is to change the gameplay.

Look at a show like "Survivor." Every season it adds new twists to constantly keep the contestants feet to the fire, and the result is often brilliance. When the "Survivor" producers made the controversial decision to divide teams by race, it started out as a questionable sideshow and finished as a deeply absorbing season. In the show's 16th, producers created two teams, one consisting of fans of the show, the other of fan favorites returning for another shot at the prize. It was arguably the show's best season ever. No one expects "Idol" producers to bring back old contestants to face off with new ones, but even a subtle twist would go a long way in energizing the show. They could resurrect the "Wild Card" show, in which each judge gets to select a contestant cut too soon and give him or her another shot. That is, after all, how Clay Aiken made it back into the mix and went on to be one of the franchise's biggest stars. Instead of having contestants choose their own songs, why not let them choose songs for one another? Or how about ending the arbitrary rule of having six men and six women in the finals? In season 6, it was clear after the first week of the semifinals that the men were outclassed, but less talented men advanced because of the inflexible rules.

At this point, no one actually thinks of "American Idol" as a platform for the country's best new talent. It is what it is: a not entirely fair, but often entertaining television show. Unless the producers start focusing on the excitement of the gameplay rather than the integrity of the competition, all adding an additional judge gets them is the assurance that at least one more person is watching.