American Idol is the highest-rated, most unstoppable force in music-television history … or is it? While the series gears up for its seventh season (which begins in January 2008) and rock fans prepare to pelt the upcoming The Next Great American Band with vitriol, the current Idols Live tour, featuring last season’s finalists like Jordin Sparks, Blake Lewis, and Phil Stacey is doing less-than-stellar business. According to today’s USA Today, the tour is halfway done, and has yet to sell out a show — in fact, nearly half the gigs weren’t even sixty-percent filled, according to stats from Billboard Boxscore. While higher ticket prices could be to blame, it’s also possible Idol is simply suffering its first significant failure. This summer, producer Nigel Lythgoe hypothesized that during season six the show was “engrossed with the mentors that were particularly good last season, and we focused on their stories and not really on the Melindas. And we didn’t know them as much as we knew the Kelly Picklers from the season before.” That’s one way of saying “our cast was sweet but dreadfully boring and personality-free.” Here’s another possible explanation for the sales slump: Maybe Sanjaya can’t sing, and while it’s fine to sit back on your couch and point and laugh at him for free, nobody wants to shell out big bucks for crappy performances. America manipulated Idol last season by keeping Sanjaya and other sub-par singers around much longer than they warranted. Now they’re voting with their wallets. Isn’t that the true American way? Season seven, we await thee …