Will tonight's episode draw even more? Spears hopes so.

When she filmed in August she tweeted: "What's up GLEEKS? Having so much fun on set! Can't wait for you guys to see the episode!"

Certainly, the show's relentless momentum seems unstoppable and there's an amusing aside to the story. Back in April at the White House Correspondents Dinner, Matthew Morrison was asked about rumours that Britney Spears wanted to star in an episode of the show. 

The rumours were sort of real. Manager Adam Leber had started a Twitter campaign for a 'Glee'/Britney episode, tweeting on April 20: "You want to see a Britney episode on Glee?"

Morrison, The 'Glee' Club's teacher in all areas Will Schuester, initially shot down the claim. "Her manager just put out the rumour. Hopefully we don't go down that road."

Oops! In the episode, Britney and other 'Glee' clubbers visit a dentist and hallucinate as a side effect of the anesthesia. So far we have seen Heather Morris, the Brittany of the title, in a scene madly reminiscent of Salma Hayek's memorable turn in 1996's 'From Dusk Till Dawn' (she's wearing a snake in a bikini in a bar). And we know John Stamos, handsome star first of 'Full House' and latterly 'ER,' is the dentist boyfriend of Emma Pillsbury, Schuester's erstwhile love (Jayma Mays).

How does Brittany end up getting all Salma Hayek? "Through a special substance, I go under and have a couple of dream sequences not only myself, but with Santana (Naya Rivera). A lot of it has to do with Will (Matthew Morrison) not allowing us to perform Britney Spears songs, because he doesn't agree with what kind of entertainer she is, so it's our fight to do Britney. But it's not just us doing Britney in the show's choir, there are other sequences and it's our homage to her."

Sounds like Morrison has a wicked good sense of humour. Here's hoping tonight's 'Glee' does too.

Watch Glee cover Britney Spears and 'Baby One More Time' below:

Nonetheless she quickly discarded the shoes after asking: "Someone come out here and take these shoes off. Obviously I'm supposed to be barefoot.

That’s nothing new for Carey and her crew. She’s often beckoned crew onstage during shows for wardrobe and microphone adjustments.  And she’s previously announced, "I need some lipstick real quick and my hair fluffed.”  She has also called in a glass of champagne.  (Wouldn’t you?) And at Madison Square Garden she announced, presumably tongue in cheek, "They say I'm a diva so, might as well act like one!”

It’s not the first time the singer has tumbled (she did that previously on US TV’s The Tonight Show in 2009). But this time Carey felt compelled to let her fans know she is fine. "TY SO much to my fans in Singapore!!!" she tweeted. "Yeah, several hectic moments, (lol!)but I tried to swirl them into festive!.Love+ God Bless."

The fall drew attention because of persistent rumours that Carey is pregnant (though the rumours have been going on for months). And while it’s not quite ‘No comment’, Carey has been resolutely opaque on the question. In her only official comment so far she said, "I appreciate everyone's well wishes, but I am very superstitious." 

Next up for Carey career-wise is the November 2 release of her second Christmas album, ‘Merry Christmas II You’.

The album features four new songs including single ‘Oh Santa’, produced by Jermaine Dupri and American Idol's Randy Jackson.

The Showbiz 411 reveals a clip of the tumble below: