Rachel performs in the season premiere. (Adam Rose/Fox)

Fox’s formerly red-hot series lost about one third of its audience in its season debut compared to last year’s. Only about 9.2 million people checked out the episode — compared to nearly 13 million who’d tuned in last fall to see the season’s first episode asap so they could tweet, blog and otherwise hyperventilate as it was airing.

Even more embarrassing for the once too-hip-to-live series, and Murphy — McKinley High’s New Directions gang got slushied — by Zooey Deschanel’s latest exercise in aren’t-I-adorable geek-itude.

Her “New Girl” comedy nabbed more than 10 million viewers immediately after “Glee.” That’s Fox’s biggest fall scripted-comedy opening in a decade – since the much ballyhooed unveiling of its Bernie Mac’s comedy.

Apparently “Glee’s” once rabid fans aren’t impressed with creator Ryan Murphy’s promise that this season the show will get back to its roots, forego celebrity guest stars, will be the last chance to bask in graduating high-schoolers Rachel, Finn and Kurt. Cast member Jane Lynch’s Emmy hosting gig on Sunday doesn’t seem to have done anything for the show either.

Meanwhile, casting is everything over on ABC’s “Dancing with the Stars.”

About 19 million people watched Monday’s season debut. About 14.8 million hung around for Tuesday’s first results show. One year earlier the Monday show bagged more than 21 million and the result night logged nearly 19 mil.

“Dancing,” in which celebrity competitors survive or get the hook each week based on a combination of judges’ scores and viewer votes, is very much dependant on which celebrities the producers are able to cast and the voting blocs those celebs bring with them. Last fall, of course, the big “get” was Bristol Palin. This year’s most buzzed-about competitor is Chaz Bono.

From which we conclude that the Tea Party/conservative political movement is far more motivated/organized when it comes to ballroom dancing competition viewing and voting than is the transgender community. We can’t wait for the navel-lint-picking op-ed pieces that will be written about this in the coming days.

So “Dancing” is down this year – but still looks good compared to its timeslot reality-series competition, NBC’s “Biggest Loser.”

The fat-farm competition series is shedding alright – viewers. What was once one of few non-football bright spots on NBC’s primetime slate attracted its smallest premiere audience ever -- a mere 6.1 million viewers on Tuesday night. (It ran more neck-and-neck with “Dancing” among 18-49 year olds because “Dancing” tends to skew old-ish because it’s, well, about ballroom dancing.)

And, after 24 hours off non-stop happy dancing upon, which had erupted at CBS when Nieslen gave word that killing off of Charlie Sheen on “Two and a Half Men” had netted them 29 million viewers, CBS suits had just enough strength left to smile broadly when they heard that 14 mil had checked out Tuesday night’s unveiling of their new Poppy-Montgomery-can’t-forget-anything cop drama, “Unforgettable.”

That’s about 1 million better than last fall’s season debut of “The Good Wife” in Tuesday’s 10 p.m. hour last fall.

“Unforgettable” towered over the season debut of ABC’s “Body of Proof” (9.4 million) and the season’s second episode of NBC’s “Parenthood” ( 5.3 million).