Well with Crystal there's actually an interesting problem. She could probably totally kill with ANY Beatles song and its a matter of choosing one among the pack that's marginally best for her.
"Across The Universe" might be interesting for Crystal. Anyone else in the current cast would totally tank with that, but she wouldn't.
Or a flat out rocker would work really well for her. "Back in the USSR", for example. Or "Revolution" would be a slam dunk. She could do the "Hey, Jude" type quiet songs just as well, but seeing her rock out would be better.
Or an odd thought... "Get Back".
Now on to Siobahn. I'd actually like to see her do a Ballad. THAT would be a change-up for her. Maybe something a BIT off center though, like "If I Fell". But I suppose if she wants to go for the predictable it would be "Let It Be".
"I've Just Seen a Face". Yes, he COULD do one of their many early R&B songs... but why be so predictable?
For some reason I see him doing "Michelle".
I have this crazy idea of Casey doing "Helter Skelter" as a Southern Rocker song.
"This Boy". Seriously. Or maybe as a backup, "And I Love Her".
Robot Katie, Hair Boy (Tim) and Andrew? No idea yet. Although I'm thinking Andrew might also be a "Helter Skelter" candidate if he re-arranges the song in a certain way.