Cassie really loves a challenge because she's chosen yet another tough cookie of a song!

Cassie's choice tonight is Eric Carmen's classic All By Myself, which was more recently popularised in the soundtrack of the first Bridget Jones movie. In fact it's a 'classic' in more ways than one because the tune is based on the classical Russian composer Sergei Rachmaninoff's Piano Concerto No. 2!

On last night's The Xtra Factor: Xcess All Areas (ITV2) Cassie was rehearsing her song in the background while vocal coach Mark Hudson chatted to Ben Shepherd. Mark wasn't totally happy with Cassie's delivery "...the power and the pitch is not the problem. The believability of what you're saying 'I'm all by myself, I don't wanna be alone anymore'. If she knows what that means and that comes out of a voice that beautiful you score big time."

Just before Cassie performs we watch her on video saying that she hopes the song isn't too big for her.

So watching Cassie take the stage tonight the big questions are 'can she handle this song?' and 'can she make it believable?'.

She is certainly giving it everything vocally. She is using her arms and body with plenty of expression. It's a big improvement on her dancing disaster of a fortnight ago!

In a similar vein to last week's performance of 'Hero' she builds the emotional intensity of the song, layer on layer,  and then releases it in a terrific crescendo of angst.

Cassie is definitely lettting out the throttle on this one!

We think she really delivered the emotion behind this song in just the way that Mark was hoping she would.

Well that's us convinced! But what about those prickly panelists Simon Cowell and Louis Walsh?

Kate: Okay, Cassie. Time for the judges' verdict! Simon Cowell.

Simon: Ahhmm... this is not going to make me very popular but who cares? Ahm, it's a song a 45 year old who's been through a hard life would sing. It's a tragic song for an older lady. Not a seventeen year old girl who's got the world at her feet. Therefore I thought the song was inappropriate and actually too big for you....I thought it was very theatrical. (a few boos - Cassie looks upset)

Sharon: Well Simon you being....(to the audience) excuse me! excuse me! ... you being not a father, you don't understand that young girls of seventeen, when they lose somebody or they're alone they feel the same as an older woman does (Sharon places her hand on her heart - cheers from the audience). They hurt the same way...(Simon is smiling, so for that matter is Cassie!) ...you know what Simon, they hurt the same way, they're happy the same way. Her hurt is the same as any other person's ...

Simon: No, no... Sharon!

Sharon: ...hurt, seventeen or forty... And she hit all the notes...unlike one of your contestants that couldn't hit the notes. That's why it was available for her to sing. Ba-da-boom! Oh yes baby!... And we didn't need anybody else in the studio to help her hit the notes. (Sharon claps her palms together dramatically) Ba-da-boom twice! (laughter drowns out Sharon's voice momentarily)...you baby!

Simon: No Kate I have to say, say something...first of all look...

Sharon: Didn't you want her to sing 'Like A Virgin'?

Simon: ...Look Sharon. We're just in disagreement of what we think is appropriate for a 17 year old, that's fine!

Sharon: Because you can't relate to a seventeen year old. You don't know any!

Simon: No, no, its...its...its not a problem! We'll just disagree!

Kate: Simon, I'm going to have to speak to Louis! (to Simon and Sharon) You agree to disagree. (to Louis) Louis Walsh? Thank you!

Louis: I totally disagree with Simon. I mean Simon this is the youngest girl in the competition!...

Simon: (under his breath) What's that got to do with it?

Louis: ...I think she's got the biggest future. I think this time next year Cassie you'll be in the West End.

Sharon: (waving her finger about frantically) And the only one that's never toured. All your artists have been in the (muffled)...

Louis: It's a very, very ambitious song Kate, but she performed it and she sang it really, really well! It's great.

(muffled sparring between Simon and Sharon can be heard whilst Louis is talking)

Kate: Cassie, very quickly. You were worried the song was too big. It's been raised tonight. Are you happy with what you did? Did you pull it off?

Cassie: Erm, I'm really happy with what I did. Erm, there are people my age and people younger than me, who at times erm, (sounding slightly choked) feel like they're by themselves and have lost people so... (puts her thumbs up in the air) ... that was for them!

Kate: Thank you very much. Okay thanks to Sharon and to Cassie! (audience applause...Kate gives Cassie a kiss and says "well done!").