I love Britney and I love Private Show but it doesn't fit her voice in my opinion. But it has the similar bluesy jazzy style which reminds me of some Adele songs like Rumour Has It and One and Only. I think Adele would annihilate Private Show vocally. She might have to tweak some of the lyrics as her image is less sexual than Britney's - maybe she could make it about an actual singing show rather than the whole 'slide down my pole' thing. Or she could take a risk and keep the lyrics the same, and go for a more sexual era with her next album. But either way I think it could definitely be her 5th #1 if she released a cover of it.