On tonight’s American Idol, the remaining six contestants will perform selections from the Andrew Lloyd Webber songbook. Ready to hear Brooke White apply her Carly Simon-vibe to a chestnut from Jesus Christ Superstar?

Is it just me or has Idol officially jumped the shark? This season is shaping up to be the show’s weakest, even with memories of Sanjaya still fresh from last year. Now comes a night dedicated to show tunes, and not just the greatest of the Great White Way (which could be entertaining) but a Webber-only showcase. All hands on dreck!

With Simon Cowell’s sour critiques ringing in my year (“It was all a bit cabaret, if I’m being honest”), tonight’s setlist seems a too-easy target for negative assessment. Will David Archuleta’s performance of a Cats classic or Carly Smithson warbling an Evita evergreen elevate either to Clarkson or Underwood status? Who knows what the contestants’ song choices will be, but I can’t imagine any rendition of “Don’t Cry For Me Argentina” will have folks dialing furiously for their favorite. (Stripped of their character/story context, I think Webber’s songs will only sound more overwrought. But maybe that’ll work if David Cook rocks out on one of ’em.)

Perhaps the producers just don’t care, and cynicism is the master they’re choosing to serve this season. Not that I want to fall into the trap of taking the show too seriously; it is a televised amateur singing contest, after all. But even Fox has to be worried that the network’s crown jewel is geting a bit tarnished, as American Idol‘s ratings are trending down.

I do have one small hope for tonight (beyond the Pennsylvania primary results): Maybe the Andrew Lloyd Webber theme will bring an abrupt end to the “waving-arms-in-unison” action from the young females in front. Week after week, I’m more irritated by it.

Of course, if a song from Starlight Express makes the broadcast, the requisite roller-skating ramps might render the pit area useless anyway.